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: 9695 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 , 9690..9719, >>Next

Mixture_Word_Problems/398250: how many ounces of pure water must be added to 75oz. of an 8% salt solution to make a 5% salt solution?
1 solutions

Answer 282206 by josmiceli(9697) About Me  on 2011-01-22 20:17:38 (Show Source):
You can put this solution on YOUR website!
.08%2A75+%2F+%28w+%2B+75%29+=+.05
6%2F%28w+%2B+75%29+=+.05
6+=+.05%2A%28w+%2B+75%29
6+=+.05w+%2B+3.75
.05w+=+2.25
w+=+45
45 ounces of pure water must be added


Expressions-with-variables/398182: Barry us paid double-time for each hour over 40. Last week he worked 47 hour and earned 486, what is his hourly rate
1 solutions

Answer 282204 by josmiceli(9697) About Me  on 2011-01-22 20:11:34 (Show Source):
You can put this solution on YOUR website!
He worked at double his rate for 7 hrs
Let x = his hourly rate
40x+%2B+7%2A2x+=+486
x%2A%2840+%2B+14%29+486
x+=+486%2F54
x+=+9
his hourly rate is $9/hr


Complex_Numbers/398218: The answer to (4sqrt(-3))(-2sqrt(-18))
1 solutions

Answer 282201 by josmiceli(9697) About Me  on 2011-01-22 20:00:13 (Show Source):


Triangles/398245: doing special right triangles (30-60-90) - if you are given a 30-60-90 triangle and the hypotenuse is 12square roots of 3 and you are not given the other lengths of the legs but you need to find the short legs length ( short leg is x and long leg is y ) what do you do to find it ?
1 solutions

Answer 282200 by josmiceli(9697) About Me  on 2011-01-22 19:50:30 (Show Source):
You can put this solution on YOUR website!
You know the ratios of the sides opposite the angles
ar as follows: (30, 60, 90) = 1, sqrt%283%29, 2
given:
The hypotenuse is 12%2Asqrt%283%29
1%2F2+=+x%2F%2812%2Asqrt%283%29%29
2x+=+12%2Asqrt%283%29
x+=+6%2Asqrt%283%29


Money_Word_Problems/398239: Job A offers an annual salary of $30,000 plus bonus of 1% of sales. Job B offers an annualsalary of $24,000 plus a bonus of 2% of sales. How much would you have to sell to earn the same amount in each job?
1 solutions

Answer 282197 by josmiceli(9697) About Me  on 2011-01-22 19:30:34 (Show Source):
You can put this solution on YOUR website!
Let s = amount of sales
Job A:
Annual salary = 30000+%2B+.01s
Job B:
Annual salary = 24000+%2B+.02s
----------------------------
Set the expression equal to each other
30000+%2B+.01s+=+24000+%2B+.02s
.01s=+6000
s+=+600000
You would have to makel $600,000
worth of sales


Evaluation_Word_Problems/398223: a 10lb mixture of peanuts and cashews sells for $5.32 per lb. The price of peanuts is $3.60 per lb and the price of cashews is $7.90 . How many lbs of each type is in the mixture
1 solutions

Answer 282177 by josmiceli(9697) About Me  on 2011-01-22 18:21:00 (Show Source):
You can put this solution on YOUR website!
Let a = pounds of peanuts in mix
Let b = pounds of cashews in mix
given:
(1) a+%2B+b+=+10 pounds
%28360a+%2B+790b%29+%2F10+=+532 (in cents)
(2) 360a+%2B+790b+=+5320
Multiply both sides 0f (1) by 360,
and subtract (1) from (2)
(2) 360a+%2B+790b+=+5320
(1) -360a+-+360b+=+-3600
430b+=+1720
b+=+4
and, since
a+%2B+b+=+10
a+=+6
There are 6 pounds of peanuts in mix
There are 4 pounds of cashews in mix
check:
%28360a+%2B+790b%29+%2F10+=+532
%28360%2A6+%2B+790%2A4%29+%2F10+=+532
%282160+%2B+3160%29%2F10+=+532
5320%2F10+=+532
532+=+532
OK


Graphs/397996: Sarah’s two student loans totaled
$12,000. One of her loans was at 6% simple interest
and the other at 9%. After one year, Sarah owed $855
in interest. What was the amount of each loan?
I got x+y=12,00 but what is the next step????
1 solutions

Answer 281999 by josmiceli(9697) About Me  on 2011-01-21 19:07:44 (Show Source):
You can put this solution on YOUR website!
If the 6% loan was for x dollars, and
the 9% loan was for y dollars, then
(1) x+%2B+y+=+12000
(2) .06x+%2B+.09y+=+855 (after 1 year)
(2) 6x+%2B+9y+=+85500
Multiply both sides of (1) by 6, then
subtract (1) from (2)
(2) 6x+%2B+9y+=+85500
(1) -6x+-+6y+=+72000
3y+=+13500
y+=+4500
and, from (1),
x+%2B+4500+=+12000
x+=+7500
The 6% loan was for $7500, and
the 9% loan was for $4500


Permutations/397991: A baseball manager chooses his lineup 1-9. How many ways can he organize his lineup if the pitcher doe not hit in the first four?
I did 9*8*7*6*6*5*4*3*2
is this correct?
1 solutions

Answer 281994 by josmiceli(9697) About Me  on 2011-01-21 18:56:50 (Show Source):
You can put this solution on YOUR website!
If the top of the lineup is considered first, there are only
8 choices for 1st batter, then 7 choices, 6, and 5
So the number of choices for the top 4 positions are
8%2A7%2A6%2A5 then the pitcher becomes available plus the
4 others left. 4+%2B+1+=+5, next here are 4 choices, then 3,
2, and 1
8%2A7%2A6%2A5%2A5%2A4%2A3%2A2%2A1+=+201600+ is the sum of all the choices
Hope I got it right


Polynomials-and-rational-expressions/397954: The are approximately 3 pounds of muscle for every 5 pounds of body weight of a certain animal. For a 105 pound animal, how much of the weight is muscle?
1 solutions

Answer 281962 by josmiceli(9697) About Me  on 2011-01-21 17:06:43 (Show Source):


Mixture_Word_Problems/397947: 1. Jacob mixes 8 liters of 4% acid solution with a 24% acid solution, which results in a 8% acid solution. Find the number of liters of 24% acid solution in the new mixture.
• Identify the variable
• Construct a table to organize the information
• Show all of your work to solve the problem.
• Write your answer as a complete sentence,
• Check your answer.
HELP PLEASE! Its due by monday and I can only do the first two problems! (Barley!)
1 solutions

Answer 281961 by josmiceli(9697) About Me  on 2011-01-21 17:02:07 (Show Source):
You can put this solution on YOUR website!
Hi, I can solve it in a straight forward algebra way. You can do all
the fancy stuff they want.
In words:
(total liters of acid you end up with)/(total liters of solution you end up with) = 8%
Let x = liters of 24% solution needed
given:
acid in 4% solution = .04%2A8+=+.32 liters
acid in 24% solution = .24x liters
-----------------------------------
%28.32+%2B+.24x%29%2F%288+%2B+x%29+=+.08
.32+%2B+.24x+=+.08%2A%288+%2B+x%29
.32+%2B+.24x+=+.64+%2B+.08x
.16x+=+.64+-+.32
.16x+=+.32
x+=+2 liters
2 liters of the 24% acid solution are needed
check answer:
%28.32+%2B+.24x%29%2F%288+%2B+x%29+=+.08
%28.32+%2B+.24%2A2%29%2F%288+%2B+2%29+=+.08
%28.32+%2B+.48%29%2F10+=+.08
.8%2F10+=+.08
.8+=+.8
OK


percentage/397941: The ticket price of the swimming pool is to be priced so that the average price is 4.4 €.
Students, unemployed, pensioners and children will receive a discount of 30%.
How much the ticket price should be set.. if 40% of visitors are entitled to a discount??
i tried and i found 10€...am i right ?
1 solutions

Answer 281948 by josmiceli(9697) About Me  on 2011-01-21 16:34:55 (Show Source):
You can put this solution on YOUR website!
Let the regular price = p
Let v = number of visitors
Then the discounted price would be p+-+.3p+=+.7p
given:
%28.6v%2Ap+%2B+.4v%2A.7%2Ap%29%2Fv+=+4.4
%28v%2Fv%29%2A%28.6p+%2B+.28p%29+=+4.4
p%2A%28.6+%2B+.28%29+=+4.4
p+=+4.4%2F.88
p+=+440%2F88
p+=+5
I get 5.


test/397939: My other algebra 2 question is find the value of x. Area of the rectangle=40ft2. xft and (x+3). How do u solve it?
1 solutions

Answer 281943 by josmiceli(9697) About Me  on 2011-01-21 16:15:45 (Show Source):
You can put this solution on YOUR website!
One side is x ft
The other side is x%2B3 ft
A+=+x%2A%28x%2B3%29
given:
A+=+40 ft2
------------
40+=+x%2A%28x%2B3%29
40+=+x%5E2+%2B+3x
x%5E2+%2B+3x+-+40+=+0
Now you can use the quadratic formula:
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a++=1
b+=+3
c+=+-40
x+=+%28-3+%2B-+sqrt%28+3%5E2-4%2A1%2A%28-40%29+%29%29%2F%282%2A1%29+
x+=+%28-3+%2B-+sqrt%28+9+%2B+160+%29%29%2F2+
x+=+%28-3+%2B-+sqrt%28+169+%29%29%2F2+
x+=+%28-3+%2B+13%29%2F2
x+=+5 ft answer
and
x+=+%28-3+-+13%29%2F2
x+=+-8 (can't use the negative root)
also,
x+%2B+3+=+8
A+=+5%2A8
A+=+40 ft2


Travel_Word_Problems/397935: a cyclist travels two and a half miles in 20 minutes. find the speed of the cyclist in miles per hour
1 solutions

Answer 281938 by josmiceli(9697) About Me  on 2011-01-21 16:01:48 (Show Source):
You can put this solution on YOUR website!
2.5%2F20 mi/min x 60 min/hr = 7.5 mi/hr


Mixture_Word_Problems/397853: Next-door neighbors Bob and Jim use hoses from both houses to fill Bob's swimming pool. They know it takes 24 h using both hoses. They also know that Bob's hose, used alone, takes 40% less time than Jim's hose alone. How much time is required to fill the pool by each hose alone?
1 solutions

Answer 281873 by josmiceli(9697) About Me  on 2011-01-21 11:39:53 (Show Source):
You can put this solution on YOUR website!
Let 1%2Fb = rate that Bob's hose alone fills pool (1 pool/ b hrs)
Let 1%2Fj = rate that Jim's hose alone fills pool (1 pool/ j hrs)
Let 1%2Fx = rate that both hoses fill pool (1 pool/ x hrs)
Then
(1) 1%2Fb+%2B+1%2Fj+=+1%2Fx
-----------------
given:
1%2Fx+=+1%2F24 (1 pool)/(24 hrs)
1%2Fb+=+1%2F%28j+-+.4j%29
(2) 1%2Fb=+1%2F%28.6j%29
and, from (1)
(1) 1%2Fb+%2B+1%2Fj+=+1%2F24
These are 2 equations and 2 unknowns, so it's solvable
By substitution:
1%2F%28.6j%29+%2B+1%2Fj+=+1%2F24
Multiply both sides by .6j
1+%2B+.6+=+%28.6j%29%2F24
.6j+=+24+%2B+14.4
j+=+38.4%2F.6
j+=+64
and, from (2),
1%2Fb+=+1%2F%28.6%2A64%29
1%2Fb+=+1%2F38.4
b+=+38.4
Bob's hose alone takes 38.4 hrs
Jim's hose alone takes 64 hrs
-------------------------
check answer:
(1) 1%2Fb+%2B+1%2Fj+=+1%2F24
1%2F38.4+%2B+1%2F64+=+1%2F24
1%2F384+%2B+1%2F640+=+1%2F240
I'll just convert to decimals:
.002604167+%2B+.0015625+=+.00416667
.004166667+=+.00416667
close enough


Probability-and-statistics/397843: Maximum numbers that can be formed using all the 4 digits 6 4 8
1 without repetition and which is divisible by 9
1 solutions

Answer 281864 by josmiceli(9697) About Me  on 2011-01-21 11:03:06 (Show Source):
You can put this solution on YOUR website!
In order to be divisible by 9, the sum of the
digits must also be divisible by 9
1+%2B+4+%2B+6+%2B+8+=+19
1+%2B+9+=+0
So, no arrangement of these digits is divisible by 9


Polynomials-and-rational-expressions/397833: Factor the expression: x^2 - 7x + 10
1 solutions

Answer 281850 by josmiceli(9697) About Me  on 2011-01-21 10:30:13 (Show Source):
You can put this solution on YOUR website!
You can do this by completing the square.
x%5E2+-+7x+=+-10
x%5E2+-+7x+%2B+%287%2F2%29%5E2+=+-+10+%2B+%287%2F2%29%5E2
x%5E2+-+7x+%2B+49%2F4+=+-+40%2F4+%2B+49%2F4
Now both sides are a perfect square
%28x+-+7%2F2%29%5E2+=+%283%2F2%29%5E2
Take the square root of both sides
(1) x+-+7%2F2+=+3%2F2
and
(2) x+-+7%2F2+=+-3%2F2
--------------
solving:
(1) x+=+7%2F2+%2B+3%2F2
(1) x+=+5
and
(2) x+-+7%2F2+=+-3%2F2
(2) x+=+7%2F2+-+3%2F2
(2) x+=+2
------------------
Then
x+-+5+=+0
x+-+2+=+0
therefore
%28x+-+2%29%2A%28x+-+5%29+=+x%5E2+-+7x+%2B+10


Travel_Word_Problems/397477: if a vehicle travels 440 miles in 7.7 seconds how fast is it going
1 solutions

Answer 281676 by josmiceli(9697) About Me  on 2011-01-20 16:18:58 (Show Source):
You can put this solution on YOUR website!
I'll convert to miles/hour
In words:
(miles/seconds)*(seconds/minute)*(minutes/hour) = miles/hour
%28440%2F7.7%29%2A%2860%2F1%29%2A%2860%2F1%29+=+1584000%2F7.7
1584000%2F7.7+=+205714.29 miles/hour


Parallelograms/397279: "If the diagonals of a rhombus are 7cm and 12cm, What is the area?"
I have no earthly idea even how to set this up in any form of an equation, ive been out of school for two weeks and im sick at home,so i havent had any help on this.
1 solutions

Answer 281610 by josmiceli(9697) About Me  on 2011-01-20 11:09:48 (Show Source):
You can put this solution on YOUR website!
A rhombus is a parallelogram with all 4 sides equal.
The diagonals intersect at right angles, and they bisect each other.
If you think of he rhombus as 2 triangles reflected about the
7 cm diagonal, then the altitudes of these triangles are
12/2 = 6 cm long. The area of 1 of these triangles is
(1/2)x7*6 = 21 cm2
Twice this area 2 x 21 = 42 cm2 is the area of the rhombus
Hope it's right


Money_Word_Problems/397281: there is $5.40 and there is 27 coins how many quater and dimes are there that make up the 5.40?
1 solutions

Answer 281595 by josmiceli(9697) About Me  on 2011-01-20 10:29:23 (Show Source):
You can put this solution on YOUR website!
Le d = number of dimes
Let q = number of quarters
given:
(1) d+%2B+q+=+27
(2) 10d+%2B+25q+=+540 (in cents)
Multiply both sides of (1) by 10,
and subtract (1) from (2)
(2) 10d+%2B+25q+=+540
(1) -10d+-+10q+=+-270
15q+=+270
q+=+18
and, since,
d+%2B+18+=+27
d+=+9
There are 9 dimes and 18 quarters
check answer:
(2) 10d+%2B+25q+=+540
10%2A9+%2B+25%2A18+=+540
90+%2B+450+=+540
540+=+540
OK


Square-cubic-other-roots/397277: Use rational exponents to simplify.
Complete the expression.
root%285%2C+x%5E20%29
1 solutions

Answer 281594 by josmiceli(9697) About Me  on 2011-01-20 10:21:07 (Show Source):


Probability-and-statistics/397264: How do I find the domain of f(x)=ln(ln(x))without using my calculator?
1 solutions

Answer 281593 by josmiceli(9697) About Me  on 2011-01-20 10:14:01 (Show Source):
You can put this solution on YOUR website!
First find the domain of ln%28x%29
x can never be negative or zero.
This is true because there is no log to any base that
can give me a (-) or (0). x can however be any (+) number
The natural log of The x's 0%3C+x+%3C1 is (-), but you
can't take the natural log of those (-) numbers, so
1+%3C=+x is the domain of f(x) = ln(ln(x))
Hope I got it


Square-cubic-other-roots/397257: Simplify by taking roots of the numerator and the denominator. Assume that all expressions under radicals represent positive numbers.
root%283%2C+27x%5E14%2Fy%5E3%29
Type an exact answer, using radicals as needed.
1 solutions

Answer 281584 by josmiceli(9697) About Me  on 2011-01-20 09:50:49 (Show Source):


Problems-with-consecutive-odd-even-integers/397247: if one number is 4 times as large as another number and the smaller number is decreased by 2 , the result is 14 less then the larger number. What is the two numbers. The numbers i got were -6 and -12. is this right
1 solutions

Answer 281579 by josmiceli(9697) About Me  on 2011-01-20 09:25:11 (Show Source):
You can put this solution on YOUR website!
I'll call the numbers J and K
given:
(1) J+=+4K
J is the larger number, K is the smaller
(2) K+-+2=+J+-+14
By substitution:
(2) K+-+2=+4K+-+14
3K+=+12
K+=+4
and, from (1),
J+=+4%2A4
J+=+16
The numbers are 16 and 4


Reduction-of-unit-multipliers/397190: A bricklayer charges $8 per square foot to lay a patio. How much would it cost for the bricklayer to lay a 12-foot-Χ-16-foot patio?

1 solutions

Answer 281551 by josmiceli(9697) About Me  on 2011-01-20 05:17:22 (Show Source):
You can put this solution on YOUR website!
12%2A16+=+192 ft2
8%2A192+=+1536
The bricklayer charges $1,536


Travel_Word_Problems/397193: train travelling @ 40kph leaves 10 mins before train travelling @ 60kph.when will they meet??
1 solutions

Answer 281550 by josmiceli(9697) About Me  on 2011-01-20 05:14:47 (Show Source):
You can put this solution on YOUR website!
How far does the 1st train get in 10 min?
d%5B1%5D+=+40%2A%281%2F6%29 (10 min is 1/6 of an hour)
d%5B1%5D+=+20%2F3 km
Now if the 2nd train has to travel d km to
meet the 1st train, then the 1st train has to
travel d+-+20%2F3 km
They will both travel for the same time period
1st train:
(1) d+-+20%2F3+=+40t
2nd train:
(2) d+=+60t
Substitute (2) in (1)
60t+-+20%2F3+=+40t
180t+-+20+=+120t
60t+=+20
t+=+1%2F3 hr
They will meet 20 min after the 2nd train leaves
check answer:
(2) d+=+60t
d+=+60%2A%281%2F3%29
d+=+20 km
and
(1) d+-+20%2F3+=+40t
20+-+20%2F3+=+40%2A%281%2F3%29
60+-+20+=+120%2A%281%2F3%29
40+=+40
OK


Money_Word_Problems/397195: An executive invested $18,000 in two accounts, one a cash on reserve that yielded 7% simple interest, and the other a long-term certificate paying 11% simple interest. At the end of one year, the two accounts had earned her a total of $1540. How much had she invested in each account?” How do i set this up as an algebra equation?
1 solutions

Answer 281549 by josmiceli(9697) About Me  on 2011-01-20 04:53:26 (Show Source):
You can put this solution on YOUR website!
Let a = amount invested @ 7%
Let b = amount invested @ 11%
given:
(1) .07a+%2B+.11b+=+1540
(2) a+%2B+b+=+18000
----------------------
Multiply both sides of (1) by 100
(1) 7a+%2B+11b+=+154000
Multiply both sides of (2) by 7
and subtract (2) from (1)
(1) 7a+%2B+11b+=+154000
(2) -7a+-+7b+=+-126000
4b+=+28000
b+=+7000
and, from (2),
a+%2B+7000+=+18000
a+=+11000
$11,000 was invested @ 7%
$7,000 was invested @ 11%





Money_Word_Problems/397188: Cicily Montague, and author from Paris, sells the movie rights to her book and will recive 600,000 euros at the end of each quarter for the next 4years. Assuming that money is worth 6% compounded quarterly, what is the value of the movie rights?
I have the answer in the back of the book $847.875.843 but i am not coming up with that as the answer i think i am setting the problem up wrong.
Please Help!
1 solutions

Answer 281548 by josmiceli(9697) About Me  on 2011-01-20 03:57:48 (Show Source):
You can put this solution on YOUR website!
Hi,
The regular compound interest rate formula which is
A+=+P%2A%281+%2B+%28r%2Fn%29%29%5E%28nt%29 does not work here because
It uses P, which is a lump of money that gets
compounded over time and gives A as a result.
I found a formula on the internet that is used for
periodic deposits in a bank, and the deposits are
compounded at a certain interst rate. The formula they
gave is:
A+=+M%28%281+%2B+%28r%2Fn%29%29%5E%28nt%29+-+1%29%2A%28n%2Fr%29
M is the regular deposit
r is the compound rate of interest
n is number of times per year interest is compounded
t is the number of years
A is amount accumulated after t years
------------------------------------------------------------
For this problem:
M = 600000 euros
r = .06
n = 4 (quarterly)
t = 4 years
-----------------------
A+=+M%28%281+%2B+%28r%2Fn%29%29%5E%28nt%29+-+1%29%2A%28n%2Fr%29
A+=+600000%28%281+%2B+%28.06%2F4%29%29%5E%284%2A4%29+-+1%29%2A%284%2F.06%29
A+=+600000%28%281+%2B+.015%29%5E16+-+1%29%2A66.6667
A+=+600000%281.26898+-+1%29%2A66.66667
A+=+600000%2A.26898%2A66.66667
A+=+600000%2A17.932001
A+=+10759200.54
I don't get the answer you're supposed to, either, so
I made a mistake, or this isn't the right formula.





Radicals/397091: Aki's Bicycle Designs has determined that when x hundred bicycles are built, the average cost per bicycle is given by C(x)=0.1x^2-0.5x+6.47, where C(x) is in hundreds of dollars. How many bicycles should the shop build to minimize the average cost per bicycles.
1 solutions

Answer 281505 by josmiceli(9697) About Me  on 2011-01-19 22:03:16 (Show Source):
You can put this solution on YOUR website!
C%28x%29=0.1x%5E2-0.5x%2B6.47
To make math easier, I'm going to say D%28x%29+=+100%2AC%28x%29
so, D%28x%29 will be in dollars
D%28x%29+=+10x%5E2+-+50x+%2B+647
In a quadratic equation the minimum occurs at x+=++-b%2F%282a%29
where the equation is of the form
ax%5E2+%2B+bx+%2B+c
-b%2F%282a%29+=+50%2F20
50%2F20+=+5%2F2
D%28x%29+=+10%285%2F2%29%5E2+-+50%2A%285%2F2%29+%2B+647
D%28x%29+=+250%2F4+-+250%2F2+%2B+647
D%28x%29+=+-250%2F4+%2B+2588%2F4
D%28x%29+=+2338%2F4
D%28x%29+=+584.5 dollars
250 bikes must be made to minimize cost at $584.50


Equations/397057: Train A and B are traveling in the same direction on parellel tracks. Train A is traveling 80 miles per hour and train B is traveling at 88 miles per hour. Train A passes a station at 6:25 P.M. If train B passes the same station at 6:40 P.M., at what time will train B catch up to train A?
(Can you inclede in the answer, either A.M. or P.M, thanks)!
1 solutions

Answer 281490 by josmiceli(9697) About Me  on 2011-01-19 21:40:49 (Show Source):
You can put this solution on YOUR website!

Train B passes the station at 6:40 PM. I know that train A
passed the station 15 min ago at 6:25 PM.
In 15 min, train A has travelled 80%2A%281%2F4%29+=+20 mi
Let d = distance train B has to go to catch train A.
Then d+-+20 is the distance train A must go to
meet B.
For train A:
d+-+20+=+80t
For train B:
d+=+88t
Substitute d in 2nd equation into 1st equation
88t+-+20+=+80t
8t+=+20
t+=+5%2F2 hr
train B will catch train A in 2.5 hrs after train B passed station.
6:40 PM + 2.5 = 9:10 PM


Average/397062: jerod has quiz scores of 90, 88, 72, and 83. What does he need tl score on his next quiz so that he has an average quiz score of 88?
1 solutions

Answer 281478 by josmiceli(9697) About Me  on 2011-01-19 21:14:00 (Show Source):
You can put this solution on YOUR website!
Let x = score of next test
%2890+%2B+88+%2B+72+%2B+83+%2B+x%29%2F5+=+88
solve for x


Linear-systems/397052: solve the linear system: x-2y=-5 , -3x+y=0 I need step by step help.
1 solutions

Answer 281476 by josmiceli(9697) About Me  on 2011-01-19 21:11:23 (Show Source):
You can put this solution on YOUR website!
Hi,
(1) x+-+2y+=+-5
(2) -3x+%2B+y+=+0
-------------
The most important rule is:
"What ever you do to one side of an equation,
you must do to the other side."
Multiply both sides of (2) by 2
then add the equations
(1) x+-+2y+=+-5
(2) -6x+%2B+2y+=+0 (notice that 2%2A0+=+0)
-5x+=+-5
x+=+1
Now substitute this value in (1)
(1) 1+-2y+=+-5
Subtract 1 from both sides
-2y+=+-5+-+1
-2y+=+-6
Divide both sides by -2
y+=+3
The solution is (1,3)