See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

Tutor:
New! Get regular updates about newly solved problems via algebra.com's RSS system.

Recent problems solved by 'josmiceli'

josmiceli answered: 9661 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149 , 9150..9179 , 9180..9209 , 9210..9239 , 9240..9269 , 9270..9299 , 9300..9329 , 9330..9359 , 9360..9389 , 9390..9419 , 9420..9449 , 9450..9479 , 9480..9509 , 9510..9539 , 9540..9569 , 9570..9599 , 9600..9629 , 9630..9659 , 9660..9689, >>Next

Money_Word_Problems/596996: The value of a new $400 bicycle decreases 20% per year. Find it's value after 2 and 3 years.
1 solutions

Answer 378011 by josmiceli(9664) About Me  on 2012-04-10 03:45:37 (Show Source):
You can put this solution on YOUR website!
after the 1st year,
+V+=+400+-+.2%2A400+
+V+=+400+-+80+
+V+=+320+
After the 2nd year,
+V+=+320+-+.2%2A320+
+V+=+320+-+64+
+V+=+256+
After the 3rd year,
+V+=+256+-+.2%2A256+
You can finish- I can't find calculator


Linear-systems/597018: solve 2x+3y+12z=900
1 solutions

Answer 378010 by josmiceli(9664) About Me  on 2012-04-10 03:31:54 (Show Source):
You can put this solution on YOUR website!
This can't be solved without more information.
In order to solve it, the number of unknowns
must equal the number of equations.
So you are missing 2 equations


Numbers_Word_Problems/596531: our hearts beat approximately 70 times per minute. Express in scientific notation how many times the heart beatsover a lifetime of 80 years. Round the decimal factor in your scientific notation to two decimal places.
1 solutions

Answer 377774 by josmiceli(9664) About Me  on 2012-04-08 20:31:45 (Show Source):
You can put this solution on YOUR website!
In terms of units:
( beats/minute) x ( minutes/hour) x ( hours/day ) x ( days/year ) x ( years/lifetime ) = beats/lifetime
+70%2A60%2A24%2A365%2A80+=+2943360000+
+2943360000+=+2.94336%2A10%5E9+
rounded off:
+2.94%2A10%5E9+


Travel_Word_Problems/596519: Ray and Sue leave the baseball stadium at the same time and head in the same direction. After 5 hours, Sue is 125 miles ahead of Ray. Sue's speed is 10 more than 2 times Ray's speed. Find the speeds of Ray and Sue.
1 solutions

Answer 377772 by josmiceli(9664) About Me  on 2012-04-08 20:21:13 (Show Source):
You can put this solution on YOUR website!
Let +s+ = Ray's speed in mi/hr
+2s+%2B+10+ = Sue's speed
In 5 hours, Ray goes
+d%5B1%5D+=+s%2A5+ mi
In 5 hours Sue goes
+d%5B2%5D+=+%28+2s+%2B+10+%29%2A5+
+d%5B2%5D+=+10s+%2B+50+ mi
-------------------
+d%5B2%5D+-+d%5B1%5D+=+125+mi%0D%0A%7B%7B%7B+10s+%2B+50+-+5s+=+125+
+5s+=+125+-+50+
+5s+=+75+
+s+=+15+
+2s+%2B+10+=+2%2A15+%2B+10+
+2s+%2B+10+=+30+%2B+10+
+2s+%2B+10+=+40+
Ray's speed is 15 mi/hr
Sue's speed is 40 mi/hr


test/596480: Hello math tutor. i need help on graphing this. i need to Graph the function: the axis of symmetry, the vertex, and the x-intercepts.
Problem:+y=-2x%5E2%2Bx-4+
Thank You!
1 solutions

Answer 377757 by josmiceli(9664) About Me  on 2012-04-08 18:49:25 (Show Source):
You can put this solution on YOUR website!
The axis of symmetry is a vertical line through
the x-coordinate of the vertex
The vertex is at +-b%2F%282a%29+ when the equation
is in the form +ax%5E2+%2B+b%2Ax+%2B+c+
+-b%2F%282a%29+=+-1%2F%282%2A%28-2%29%29+
+-b%2F%282a%29+=+1%2F4+
Now find +y%28+1%2F4+%29+
+y%281%2F4%29+=+-2%2A%281%2F4%29%5E2+%2B+1%2F4+-+4+
+y%281%2F4%29+=+-1%2F8+%2B+2%2F8+-+32%2F8+
+y%281%2F4%29+=+-31%2F8+
The vertex is at ( 1/4, -31/8 )
The axis of symmetry is +x+=+1%2F4+
-------------------------------
Find the x-intercepts by setting +y+=+0+
:+y+=+-2x%5E2+%2B+x+-+4+
:+-2x%5E2+%2B+x+-+4+=+0+
Use the quadratic formula
+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+a+=+-2+
+b+=+1+
+c+=+-4+
+x+=+%28-1+%2B-+sqrt%28+1%5E2+-+4%2A%28-2%29%2A%28-4%29+%29%29+%2F+%282%2A%28-2%29%29+
+x+=+%28-1+%2B-+sqrt%28+1+-+32+%29%29+%2F+%28-4%29+
+x+=+%281+%2B+sqrt%28+31+%29+%2Ai%29+%2F+4+
and
+x+=+%281+-+sqrt%28+31+%29+%2Ai%29+%2F+4+
The roots are imaginary, so there are no x-intercepts
here's a plot:
+graph%28+400%2C+400%2C+-4%2C+4%2C+-10%2C+2%2C+-2x%5E2+%2B+x+-+4+%29+


Linear_Equations_And_Systems_Word_Problems/596472: A pharmacist wants to make 18 ml of a 6% hydrogen peroxide solution. How many mls of 5% hydrogen peroxide must he mix with 7% hydrogen peroxide to make the desired solution?
1 solutions

Answer 377755 by josmiceli(9664) About Me  on 2012-04-08 18:24:43 (Show Source):
You can put this solution on YOUR website!
Let +a+ = ml of 5% solution needed
Let +b+ = ml of 7% solution needed
+.05a+ = ml of hydrogen peroxide in 5% solution
+.07b+ = ml of hydrogen peroxide in 7% solution
----------------------------------------
given:
(1) +a+%2B+b+=+18+
(2) +%28+.05a+%2B+.07b+%29+%2F+18+=+.06+
--------------------------
(2) ++.05a+%2B+.07b++=+.06%2A18+
(2) ++.05a+%2B+.07b++=+1.08+
(2) +5a+%2B+7b+=+108+
Multiply both sides of (1) by 5 and
subtract (1) from (2)
(2) +5a+%2B+7b+=+108+
(1) +-5a+-+5b+=+-90+
+2b+=+18+
+b+=+9+
and, since
(1) +a+%2B+b+=+18+
(1) +a+%2B+9+=+18+
(1) +a+=+9+
9 ml of 5% solution is needed
9 ml of 7% solution is needed
check:
(2) +%28+.05a+%2B+.07b+%29+%2F+18+=+.06+
(2) +%28+.05%2A9+%2B+.07%2A9+%29+%2F+18+=+.06+
(2) +%28+.45+%2B+.63+%29+%2F+18+=+.06+
(2) +1.08+%2F+18+=+.06+
(2) +1.08+=+.06%2A18+
(2) +1.08+=+1.08+
OK


Rate-of-work-word-problems/596408: a push mower can mow a large area for 6 hours where as a mower with a riding mower van mow for 5 hours, working together how long will it take to mow the lawn
1 solutions

Answer 377715 by josmiceli(9664) About Me  on 2012-04-08 14:22:34 (Show Source):
You can put this solution on YOUR website!
Add their rates of mowing to get their
rate working together
Rate of push mower: ( 1 area ) / ( 6 hrs )
Rate of riding mower: ( 1 area ) / ( 5 hrs )
Let +t+ = time in hrs to mow 1 area working together
Rate working together: ( 1 area ) / ( t hrs )
-------------------------
+1%2F6+%2B+1%2F5+=+1%2Ft+
Multiply both sides by +6%2A5%2At+
+5t+%2B+6t+=+5%2A6+
+11t+=+30+
+t+=+2.73+
It will take 2.73 hrs
This is about 2 hrs and 44 min ( .73*60 = 44 )


Travel_Word_Problems/596396: An express train travels 150 miles in the same time a freight train goes 100 miles. Find their average speeds if the freight train travels 20 mph less than the express train
1 solutions

Answer 377712 by josmiceli(9664) About Me  on 2012-04-08 14:14:23 (Show Source):
You can put this solution on YOUR website!
L:et +t+ = the same time for both trains in hours
Let +s+ = the speed of the express train in mi/hr
+s+-+20+ = the speed of the freight train in mi/hr
----------------
Equation for express train:
(1) +150+=+s%2At+
Equation for freight train:
(2) +100+=+%28+s+-+20+%29%2At+
----------------
(2) +100+=+s%2At+-+20t+
Substitute (1) into (2)
(2) +100+=+150+-+20t+
(2) +20t+=+150+-+100+
(2) +20t+=+50+
(2) +t+=+2.5+ hrs
----------------
(1) +150+=+s%2At+
(1) +150+=+s%2A2.5+
(1) +s+=+150%2F2.5+
(1) +s+=+60+ mi/hr
and
(2) +100+=+%28+s+-+20+%29%2At+
(2) +100+=+%28+s+-+20+%29%2A2.5+
(2) +100+%2F+2.5+=+s+-+20+
(2) +s+-+20+=+40+
-----------------
The average speed of the express train in 60 mi/hr
The average speed of the freight train in 40 mi/hr


Percentage-and-ratio-word-problems/596400: What is 1,200 over 3,000 simplified?
1 solutions

Answer 377711 by josmiceli(9664) About Me  on 2012-04-08 14:01:50 (Show Source):
You can put this solution on YOUR website!
+1200+%2F+3000+
Divide top and bottom by +1000+
This doesn't change the value of
the fraction.
+1.2+%2F+3+
Do the division
+1.2+%2F+3+=+.4+
also
+.4+=+4%2F10+
+4%2F10+=+2%2F5+ answer


Quadratic_Equations/596397: how do i write a quadratic equation from: two people drop rocks from different heights at the same time. the first from 400ft and the second from 160ft.write two functions that describe the heights of the rocks.?
1 solutions

Answer 377710 by josmiceli(9664) About Me  on 2012-04-08 13:56:48 (Show Source):
You can put this solution on YOUR website!
The equations would be:
(1) +h%28t%29+=+-16t%5E2+%2B+400+
and
(2) +h%28t%29+=+-16t%5E2+%2B+160+
+h+ is in feet, +t+ is in seconds
---------------------
Notice that for both (1) and (2),
if +t+=+0+ ( just letting of rocks ), then
(1) +h%280%29+=+400+
(2) +h%280%29+=+160+
-----------------
You also want to know +h%28t%29+=+0+, which
means the rock has hit the ground.
You don't want +h%28t%29+ to ever be negative,
since the rock would have to burrow into the
ground.
------------------
The equations would be:
(1) +-16t%5E2+%2B+400+=+0+
(1) +-16t%5E2+=+-400+
(1) +t%5E2+=+25+
(1) +t+=+5+
Notice that in 5.1 sec, the stone is still resting
on the ground, and hasn't burrowed into the
ground as the equation would show, ( negative h )
and
(2) +-16t%5E2+%2B+160+=+0+
(2) +-16t%5E2+=+-160+
(2) +t%5E2+=+10+
(2) +t+=+3.162+
-----------------


Polynomials-and-rational-expressions/596265: How will the graph of 1/2x^2+3 change if the coefficient of x^2 becomes 2?
1 solutions

Answer 377649 by josmiceli(9664) About Me  on 2012-04-07 21:14:57 (Show Source):
You can put this solution on YOUR website!
Here are plots of
+%281%2F2%29%2Ax%5E2+%2B+3+ and
+2x%5E2+%2B+3+

The plot is 4 times narrower since +2+=+4%2A%281%2F2%29+
For the same +x+, +f%28x%29+ is about 4 times greater


Equations/596272: x^4-5x^2-36
Help me. How do you factorize this problem?
1 solutions

Answer 377644 by josmiceli(9664) About Me  on 2012-04-07 21:04:47 (Show Source):
You can put this solution on YOUR website!
+x%5E4+-+5x%5E2+-+36+
Let +z+=+x%5E2+
+z%5E2+-++5z+-+36+
Complete the square
+z%5E2+-++5z+-+36+=+0+
+z%5E2+-++5z+=+36+
+z%5E2+-+5z+%2B+%285%2F2%29%5E2+=+36+%2B+%285%2F2%29%5E2+
+z%5E2+-+5z+%2B+25%2F4+=+144%2F4+%2B+25%2F4+
+z%5E2+-+5z+%2B+25%2F4+=+169%2F4+
+%28+z+-+5%2F2+%29%5E2+=+%28+13%2F2+%29%5E2+
Take the square root of both sides
+z+-+5%2F2+=+13%2F2+
+2z+-+5+=+13+
+2z+-+18+=+0+
+z+-+9+=+0+
and, also
+z+-+5%2F2+=+-13%2F2+
+2z+-+5+=+-13+
+2z+%2B+8+=+0+
+z+%2B+4+=+0+
-------------
The factoring is
+%28+z+-+9+%29%2A%28+z+%2B+4+%29+
and, since
+z+=+x%5E2+
+%28+x%5E2+-+9+%29%2A%28+x%5E2+%2B+4+%29+
This can be further factored into
+%28+x+%2B+3+%29%2A%28+x+-+3+%29%2A%28+x%5E2+%2B+4+%29+


Numbers_Word_Problems/596187: Larry has 66 music CDs. He has 2 times as many rock CDs as country CDs. He has
3 times as many rock CDs as hip-hop CDs.
How many rock CDs does Larry have? Please show me the steps.
1 solutions

Answer 377579 by josmiceli(9664) About Me  on 2012-04-07 14:04:15 (Show Source):
You can put this solution on YOUR website!
Let +a+ = number of country CD's
Let +b+ = number of rock CD's
+b+=+2a+
+c+ = number of hip-hop CD's
+b+=+3c+
----------------------------
+a+%2B+b+%2B+c+=+66+
+b+=+2a+
+a+=+b%2F2+
and
+b+=+3c+
+c+=+b%2F3+
-----------
By substitution:
+b%2F2+%2B+b+%2B+b%2F3+=+66+
Multiply both sides by 6
+3b+%2B+6b+%2B+2b+=+396+
+11b+=+396+
+b+=+36+
and, since
+a+=+b%2F2+
+a+=+36%2F2+
+a+=+18+
also,
+c+=+b%2F3+
+c+=+36%2F3+
+c+=+12+
Larry has 36 rock CD's
check:
+a+%2B+b+%2B+c+=+66+
+18+%2B+36+%2B+12+=+66+
+66+=+66+
OK


Graphs/596105: 10 Men begin to work together on a job, but after some days, 4 of them left the job. As a
result the job which could have been completed in 40 days is completed in 50 days. How
many days after the commencement of the work did the 4 men leave?
(a) 25 (b) 30 (c) 10 (d) 15
1 solutions

Answer 377556 by josmiceli(9664) About Me  on 2012-04-07 12:55:59 (Show Source):
You can put this solution on YOUR website!
This says that 10 men could have done the job
in 40 days.
1 man would have taken 10 times as long, so
1 man does the job in 400 days
Let +n+ = number of days after start when 4 men leave job
+50+-+n+ = number of days after 4 men leave
-----------------
In general, ( rate of working for 1 man ) x ( number of men ) x ( number of days ) = part of job completed
( 1 job / 400 days ) x ( 10 men ) x ( n days ) = part of job completed
( 1 job / 400 days ) x ( 6 men ) x ( 50 - n days ) = part of job completed
The 2 parts add up to 1 job completed
-----------------
+%28+1%2F400+%29%2A10n+%2B+%28+1%2F400+%29%2A6%2A%28+50+-+n+%29+=+1+
+%28+1%2F400+%29%2A%28+10n+%2B+300+-+6n+%29+=+1+
+4n+%2B+300+=+400+
+4n+=+100+
+n+=+25+
+50+-+n+=+50+-+25+
+50+-+n+=+25+
The 4 men left 25 days after the work started
check:
+%28+1%2F400+%29%2A10n+%2B+%28+1%2F400+%29%2A6%2A%28+50+-+n+%29+=+1+
+%28+1%2F400+%29%2A10%2A25+%2B+%28+1%2F400+%29%2A6%2A%28+50+-+25+%29+=+1+
+250%2F400+%2B+%28+6%2A25+%29+%2F+400+=+1+
+250+%2B+150+=+400+
+400+=+400+
OK


Human-and-algebraic-language/596155: Hello,
I have problems with word problems and I always have. Now I am in Algebra I and so they are harder. I have tried so hard on them but I still don't understand them. If you could give me some tips on how to solve algebraic word problems I would greatly appreciate it.
Thanks
1 solutions

Answer 377547 by josmiceli(9664) About Me  on 2012-04-07 12:13:29 (Show Source):
You can put this solution on YOUR website!
(1)
Look at the unknown or unknowns that they are looking for.
Right away, make the statements:
Let ( first unknown quantity ) = ( some letter )
Let ( second unknown quantity ) = ( some different letter )
etc.
Choose the letters so they are the 1st letter of the unknown quantity ( usually )
(2)
There are categories of word problems.
Decide what the category is. Some of the categories are:
(a) Mixture problems
(b) related rate problems ( 2 planes, 2 cars, etc. )
(c) Work problems ( how long to finish a job with 2 people, etc )
That's the majority of word problems
-------------------------------
There are critical thing to grasp about each category of problem
I solve a lot of these types, and if you go through my solutions,
I think you'll get how I did them. Click on "our tutors". I am close
to the top of the list: "josmiceli".
Then click on my solutions, and scroll through until you find
the general category you need. Hope this helps.


Linear_Equations_And_Systems_Word_Problems/596151: For a special event at the TCR spring fest, the cost of 3 adult tickets and 4 student tickets was $84 and the cost of 4 adult tickets and 2 student tickets was $62. find the admission price for an adult ticket and for a student ticket at the spring fest.
1 solutions

Answer 377546 by josmiceli(9664) About Me  on 2012-04-07 11:55:30 (Show Source):
You can put this solution on YOUR website!
Let +a+ = the cost of an adult ticket
Let +s+ = the cost of a student ticket
given:
(1) +3a+%2B+4s+=+84+
(2) +4a+%2B+2s+=+62+
------------------
Multiply both sides of (2) by +2+
and subtract (1) from (2)
(2) +8a+%2B+4s+=+124+
(1) +-3a+-+4s+=+-84+
+5a+=+40+
+a+=+8+
and, since
(2) +4a+%2B+2s+=+62+
(2) +32+%2B+2s+=+62+
(2) +2s+=+30+
(2) +s+=+15+
An adult ticket is $8
A student ticket is $15
check:
(1) +3%2A8+%2B+4%2A15+=+84+
(1) +24+%2B+60+=+84+
(1) +84+=+84+
OK


Quadratic_Equations/596123: 9x2(power 2) + 6x = -1. Put in quadratic formula and solve
1 solutions

Answer 377545 by josmiceli(9664) About Me  on 2012-04-07 11:42:52 (Show Source):
You can put this solution on YOUR website!
+9x%5E2+%2B+6x++=+-1+
+9x%5E2+%2B+6x+%2B+1+=+0+
This is in the form +ax%5E2+%2B+b%2Ax+%2B+c+=+0+
The quadratic formula is
+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+a+=+9+
+b+=+6+
+c+=+1+
+x+=+%28+-6+%2B-+sqrt%28+6%5E2+-+4%2A9%2A1+%29%29+%2F+%282%2A9%29+
+x+=+%28+-6+%2B-+sqrt%28+36+-+36+%29%29+%2F+18+
+x+=+%28+-6+%2B-+sqrt%28+0+%29%29+%2F+18+
+x+=++-%286+%2F+18%29+
+x+=+-%281%2F3%29+ answer
check:
+x+%2B+1%2F3+=+0+
+3x+%2B+1+=+0+
This is a double root, so
+%28+3x+%2B+1+%29%2A%28+3x+%2B+1+%29+=+0+
+9x%5E2+%2B+6x+%2B+1+=+0+
OK


Travel_Word_Problems/596098: two travel from same point, one reaches point a in 7 minutes other in 9 minutes. when will they meet at the same point at the same time?
1 solutions

Answer 377515 by josmiceli(9664) About Me  on 2012-04-07 00:38:05 (Show Source):
You can put this solution on YOUR website!
It will never happen.
If time = +t+, their separation in distance
will be +%28a%2F7%29%2At+-+%28a%2F9%29%2At+=+%28+1%2F7+-+1%2F9%29%2Aa%2At+
-----------------
The slower one, the one that takes 9 min to reach
point a, needs a headstart for them to meet at the
same point at the same time.



Polynomials-and-rational-expressions/596032: The nutty shoppe has 10kg of mixed pecans and cashews which sell for $8.40 per kilogram. Cashews alone sell for $8.00 per kilogram, and pecans sell for $9.00 per kilogram. How many kilograms of pecans are there in the mix?
1 solutions

Answer 377489 by josmiceli(9664) About Me  on 2012-04-06 21:04:38 (Show Source):
You can put this solution on YOUR website!
Let +p+ = kg of pecans
Let +c+ = kg of cashews
Cost of pecans used = +9p+
Cost of cashews used = +8c+
Cost of mixture = +8.4%2A10+=+84+
---------------------------
(1) +9p+%2B+8c+=+84+
(2) +p+%2B+c+=+10+
-----------------
Multiply both sides of (2) by +8+
and subtract (2) from (1)
(1) +9p+%2B+8c+=+84+
(2) +-8p+-+8c+=+-80+
+p+=+4+
and, since
(2) +p+%2B+c+=+10+
(2) +4+%2B+c+=+10+
(2) +c+=+6+
-------------
There are 4 kg of pecans in the mixture
check answer:
(1) +9p+%2B+8c+=+84+
(1) +9%2A4+%2B+8%2A6+=+84+
(1) +36+%2B+48+=+84+
(1) +84+=+84+
OK


Quadratic_Equations/593460: Together Maria and Johannes can pick a bushel of apples in 16 minutes. Maria takes 4 minutes more to pick a bushel than Johannes does. Find the time it takes each person to pick a bushel of apples alone.
1 solutions

Answer 376338 by josmiceli(9664) About Me  on 2012-03-29 22:01:03 (Show Source):
You can put this solution on YOUR website!
Add their individual rates of picing to get
their rate of picking together
Together, rate = ( 1 bushel ) / ( 16 min )
Let +t+ = Johanne's time ion minutes to pick 1 bushel
+t+%2B+4+ = Maria's time in minutes to pick 1 bushel
--------------------------------
+1%2Ft+%2B+1%2F%28+t+%2B+4+%29+=+1%2F16+
Multiply both sides by +16t%2A%28+t+%2B+4+%29+
+16%2A%28+t+%2B+4+%29+%2B+16t+=+t%2A%28+t+%2B+4+%29+
+16t+%2B+64+%2B+16t+=+t%5E2+%2B+4t+
+t%5E2+-+32t+%2B+4t+-+64+=+0+
+t%5E2+-+28t+-+64+=+0+
Use quadratic formula
t+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+a+=+1+
+b+=+-28+
+c+=+-64+
+t+=+%28-%28-28%29+%2B-+sqrt%28+%28-28%29%5E2+-+4%2A1%2A%28-64%29+%29%29+%2F+%282%2A1%29+
+t+=+%28+28+%2B-+sqrt%28+784+%2B+256+%29%29+%2F+2+
+t+=+%28+28+%2B-+sqrt%28+1040+%29%29+%2F+2+
+t+=+%28+28+%2B+32.25%29+%2F+2+ ( using the (-) sqrt gives negative time: ignore )
+t+=+60.25%2F2+
+t+=+30.125+
+t+%2B+4+=+34.125+
Johanne takes 30.125 min picking alone
Maria takes 34.125 min picking alone
check:
+1%2Ft+%2B+1%2F%28+t+%2B+4+%29+=+1%2F16+
+1%2F30.125+%2B+1%2F34.125+=+1%2F16+
+.0332+%2B+.0293+=+.0625+
+.0625+=+.0625+
OK


Polynomials-and-rational-expressions/593005: If there is anyone who can help me with this multiplication process with polynomials I would appreciate it greatly
(5x+5)(5x+5)
1 solutions

Answer 376152 by josmiceli(9664) About Me  on 2012-03-28 21:47:34 (Show Source):
You can put this solution on YOUR website!
Use the general rule that says
+%28+a+%2B+b+%29%2A%28+c+%2B+d+%29+=+a%2Ac+%2B+b%2Ac+%2B+a%2Ad+%2B+b%2Ad+
First, factor out all the 5's
+%285x%2B5%29%285x%2B5%29+=+5%2A%28+x+%2B+1+%29%2A%28+x+%2B+1+%29+
Using the above general rule:
+%285x%2B5%29%285x%2B5%29+=+5%2A%28+x%5E2+%2B+x+%2B+x+%2B+1+%29+
+%285x%2B5%29%285x%2B5%29+=+5%2A%28+x%5E2+%2B+2x+%2B+1+%29+
+%285x%2B5%29%285x%2B5%29+=+5x%5E2+%2B+10x+%2B+5+%29+


Mixture_Word_Problems/593021: How many liters of water must be added to a 70 liter of a 40% aid solution in order to produce a 28% acid solution?
1 solutions

Answer 376150 by josmiceli(9664) About Me  on 2012-03-28 21:37:39 (Show Source):
You can put this solution on YOUR website!
Let +w+ = liters of water needed
+.4%2A70+ = acid in 40% solution
----------
+%28+.4%2A70%29+%2F+%28+70+%2B+w+%29+=+.28+
+28+=+.28%2A%28+70+%2B+w+%29+
+70+%2B+w+=+100+
+w+=+30+
30 liters of water is needed


Travel_Word_Problems/593008: 2. A train required 2 h longer to travel 500 km than a plane required to travel 1200 km. Find the speed of the train, if the plane travels 4 times as fast as the train.
1 solutions

Answer 376148 by josmiceli(9664) About Me  on 2012-03-28 21:32:02 (Show Source):
You can put this solution on YOUR website!
Let +s+ = the speed of the train
+4s+ = the speed of the plane
Let +t+ = time for the plane
+t+%2B+2+ = time for the train
---------
Equation for the train:
(1) +500+=+s%2A%28+t+%2B+2+%29+
Equation for the plane:
(2) +1200+=+4s%2At+
---------------
This is 2 equations and 2 unknowns,
so it's solvable
(1) +500+=+s%2At+%2B+2s+
and
(2) +s%2At+=+1200%2F4+
(2) +s%2At+=+300+
Substitute (2) into (1)
(1) +500+=+300+%2B+2s+
(1) +2s+=+200+
(1) +s+=+100+
The speed of the train is 100 km/hr
check:
(2) +1200+=+4s%2At+
(2) +1200+=+4%2A100%2At+
(2) +t+=+3+
and
(1) +500+=+s%2A%28+t+%2B+2+%29+
(1) +500+=+100%2A%28+3+%2B+2+%29+
(1) +500+=+100%2A5+
(1) +500+=+500+
OK


�t�e�s�t/593010: How do you know what the right angle side is in a right angles?
1 solutions

Answer 376144 by josmiceli(9664) About Me  on 2012-03-28 21:14:30 (Show Source):
You can put this solution on YOUR website!
Use the Pythagorean theorem
+h%5E2+=+a%5E2+%2B+b%5E2+
where h is the side opposite
the right angle
-------------
If you don't know a and b, which are
the other 2 sides, then you have to find
h some other way.


Linear_Equations_And_Systems_Word_Problems/593009: A quiz is worth 40 points. You want a 35 point average for all 5 quizzes. You already took 4 squizzes wit?h scores of 32,38,36 and 33. What must your score be on your final quiz to reach your average
1 solutions

Answer 376143 by josmiceli(9664) About Me  on 2012-03-28 21:09:20 (Show Source):
You can put this solution on YOUR website!
Using the definition of an average,
+%28+32+%2B+38+%2B+36+%2B+33+%2B+x+%29+%2F+5+=+35+
+139+%2B+x+=+175+
+x+=+175+-+139+
+x+=+36+
Your score must be 36


test/592994: You spend 1/4 for tickets, 1/2 for parking. You have $18 left over. How much money did you start with? Teacher wants it to be figured out by pie chart. Help
1 solutions

Answer 376142 by josmiceli(9664) About Me  on 2012-03-28 21:01:37 (Show Source):
You can put this solution on YOUR website!
The whole pie would be the amount you started with
Draw a line through the center and label half of the
pie as "parking"
Now divide the other 1/2 of a pie into 2 equal parts
Label 1/2 as "tickets"
Label the other half as $18
--------------------
Now you can see that "tickets" has to
equal $18 also, and "parking" must be
$18 + $18 = $36
So, the whole pie is $18 + $18 + $36 = $72
which is what you started with.


Graphs/592992: How do I graph y = (1/2)squared
1 solutions

Answer 376140 by josmiceli(9664) About Me  on 2012-03-28 20:45:16 (Show Source):
You can put this solution on YOUR website!
This is just y = a number.
This means that no matter where you are on
this line, y does not change. the x component
can change and be anything.
-------------
The only line that does this is a horizontal line.
+y+=+%281%2F2%29%5E2+
+y+=+1%2F4+
This is a horizontal line intersecting the y-axis
at (0,1/4), and goes infinitely far in both
(-) and (+) directions


Age_Word_Problems/592116: Five years ago, the age of the father was thrice the age of his son. In five years time, the age of father will be twice the age of his son at that time. Find their present ages.
1 solutions

Answer 375842 by josmiceli(9664) About Me  on 2012-03-27 04:14:17 (Show Source):
You can put this solution on YOUR website!
Let +f+ = Father's age now
Let +s+ = Son's age now
given:
(1) +f+-+5+=+3%2A%28+s+-+5+%29+
(2) +f+%2B+5+=+2%2A%28+s+%2B+5+%29+
--------------------
(1) +f+-+5+=+3s+-+15+
(1) +3s+-+f+=+10+
and
(2) +f+%2B+5+=+2s+%2B+10+
(2) +2s+-+f+=+-5+
Subtract (2) from (1)
(1) +3s+-+f+=+10+
(2) +-2s+%2B+f+=+5+
+s+=+15+
and
(1) +3s+-+f+=+10+
(1) +3%2A15+-+f+=+10+
(1) +45+-+f+=+10+
(1) +f+=+45+-+10+
(1) +f+=+35+
Father is 35 and Son is 15
check:
(1) +f+-+5+=+3%2A%28+s+-+5+%29+
(1) +35+-+5+=+3%2A%28+15+-+5+%29+
(1) +30+=+3%2A10+
(1) +30+=+30+
OK
(2) +f+%2B+5+=+2%2A%28+s+%2B+5+%29+
(2) +35+%2B+5+=+2%2A%28+15+%2B+5+%29+
(2) +40+=+2%2A20+
(2) +40+=+40+
OK


Average/592123: Lauren has grades of 98 and 86 on her first two
chemistry quizzes. What must she score on her
third quiz to have an average of at least 91 on the
three quizzes?
1 solutions

Answer 375840 by josmiceli(9664) About Me  on 2012-03-27 03:56:03 (Show Source):
You can put this solution on YOUR website!
+%28+98+%2B+86+%2B+x+%29+%2F+3+=+91+{
+184+%2B+x+=+3%2A91+
+x+=+273+-184+
+x+=+89+
She must score at least 89


Quadratic_Equations/591991: how do i factor the trinomial -x^2 - 11X + 180
1 solutions

Answer 375815 by josmiceli(9664) About Me  on 2012-03-26 22:17:42 (Show Source):
You can put this solution on YOUR website!
+-x%5E2+-+11x+%2B+180+
Use quadratic formula
+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+a+=+-1+
+b+=+-11+
+c+=+180+
+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+

+x+=+%28+11+%2B-+sqrt%28+121+%2B+720+%29%29+%2F+%28-2+%29+
+x+=+%28+11+%2B-+sqrt%28+841+%29%29+%2F+%28-2+%29+
+x+=+%28+11+%2B+29+%29+%2F+%28-2+%29+
+x+=+40%2F%28-2%29+
+x+=+-20+
and
+x+=+%28+11+-+29+%29+%2F+%28-2%29+
+x+=+%28-18%29+%2F+%28-2%29+
+x+=+9+
------------
Rewriting the answers,
+-x+-+20+=+0+
+x+-+9+=+0+
+%28-+x+-+20+%29%2A%28+x+-+9+%29+=++-x%5E2+-+20x+%2B+9x+%2B+180+
+%28-+x+-+20+%29%2A%28+x+-+9+%29+=++-x%5E2+-+11x+%2B+180+


Linear-equations/592012: we have a dakota step review. i do not under stand how to know what the slope is or the linear function table to lines on pictures. so please explain how to. thanks!
1 solutions

Answer 375810 by josmiceli(9664) About Me  on 2012-03-26 21:33:38 (Show Source):
You can put this solution on YOUR website!
You need to sit down with someone who really
knows it and can explain it. Is there any student
who could? They might do it for some kind of trade.
No one could do this over the internet.
Falling behind is tough- I've been there.
Just keep asking for help, and good luck.