New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'checkley77'
checkley77 answered: 7072 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, >>Next
Pythagorean-theorem/241321: the sides of a triangle are 8, 15 and 17 units. if each side is doubled, by how many square units will the area of the triangle increase?
1 solutions
Answer 176860 by checkley77(7072)   on 2009-11-21 19:45:02 (Show Source):
You can put this solution on YOUR website!If this is a right triangle then:
area=bh/2
area=15*8/2
area=60 square units.
area=30*16/2
area=240 square units.
The area has increased by 240-60=180 square units or a 4 fold increase.
|
Evaluation_Word_Problems/241444: If you double a number and then add 12, you get one-half of the original number. What is the oringinal number? I tried this problem and my answer was 8, but i wasn't sure if it was correct.
1 solutions
Answer 176848 by checkley77(7072) on 2009-11-21 19:09:32 (Show Source):
|
Mixture_Word_Problems/241446: The manager of a bulk foods establishment sells a trail mix for $6 per pound and premium cashews for $12 per pound. The manager wishes to make a 135-pound trail mix-cashew mixture that will sell for $10 per pound. How many pounds of each should be used?
1 solutions
Answer 176847 by checkley77(7072) on 2009-11-21 19:06:41 (Show Source):
You can put this solution on YOUR website!12X+6(135-X)=135*10
12X+810-6X=1350
6X=1350-810
6X=540
X=540/6
X=90 LBS. OF $12 CASHEWS IS USED.
135-90=45 LBS. OF $6 TRAIL MIX IS USED.
PROOF:
12*90+6*45=135*10
1080+270=1350
1350=1350
|
Linear-systems/241396: 4x-5y=11
x+2y=7
1 solutions
Answer 176843 by checkley77(7072) on 2009-11-21 18:57:30 (Show Source):
You can put this solution on YOUR website!4x-5y=11
-5y=-4x+11
y=-4x/-5+11/-5
y=4x/5-11/5 (red line)
x+2y=7
2y=-x+7
y=-x/2+7/2
y=-x/2+7/2 (green line)
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions 4x/5 -11/5 and -x/2 +7/2).
4x-5y=11
x+2y=7 multiply this equation by -4 & add
-4x-8y=-28
4x-5y=11
----------------
-13y=-17
y=-17/-13
y=17/13 or 1.3 ans.
x+2*17/13=7
x+34/13=7
x=7-34/13
x=4.38 ans.
Intercept (4.38,1.30)
|
Graphs/241406: Find the soultion to the system of equations.
8x - 5y = 31
x - 4y = 14
1 solutions
Answer 176832 by checkley77(7072) on 2009-11-21 18:24:46 (Show Source):
You can put this solution on YOUR website!8x - 5y = 31
x - 4y = 14 multiply by -8 & add.
-8x+32y=-112
8x-5y=31
------------------
27y=-81
y=-81/27
y=-3 ans.
8x-5*-3=31
8x+15=31
8x=31-15
8x=16
x=16/8
x=2 ans.
Proof:
2-4*-3=14
2+12=14
14=14
|
Coordinate-system/241415: find the x-internet. round to the nearest tenth:
1 solutions
Answer 176829 by checkley77(7072) on 2009-11-21 18:10:42 (Show Source):
You can put this solution on YOUR website! red line
set y=0 & solve for the x values.
4x^2=7
x^2=7/4
x=sqrt1.75
x=+-1.3 ans.
green line
set y=0 & solve for the x values.
3x^2+2x-5=0
(3x+5)(x-1)=0
3x+5=0
3x=-5
x=-5/3
x=-1.7 ans.
x-1=0
x=1 ans.
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions 4x^2 -7 and 3x^2 +2x -5).
|
Coordinate-system/241420: find the x-internet. round to the nearest tenth:
1 solutions
Answer 176828 by checkley77(7072) on 2009-11-21 18:07:06 (Show Source):
You can put this solution on YOUR website! red line
set y=0 & solve for the x values.
4x^2=7
x^2=7/4
x=sqrt1.75
x=+-1.3229 ans.
green line
set y=0 & solve for the x values.
3x^2+2x-5=0
(3x+5)(x-1)=0
3x+5=0
3x=-5
x=-5/3
x=-1.667 ans.
x-1=0
x=1 ans.
(graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions 4x^2 -7 and 3x^2 +2x -5).
|
Triangles/241435: The height of a triangle is 1cm less than the length of the base. The area is 1770cm squared. Find the height.
1 solutions
Answer 176813 by checkley77(7072) on 2009-11-21 17:27:05 (Show Source):
You can put this solution on YOUR website!A=BH/2
H=B-1
1770=B(B-1)/2
1770*2=B^2-B
B^2-B=3,540
B^2-B-3,540=0
(B-60)(B+59)=0
B-60=0
B=60 CM.
H=60-1=59 CM. ANS. FOR THE HEIGHT.
PROOF:
1770=60*59/2
1,770=3,540/2
1,770=1,770
|
Linear-systems/241438: Find the soultion to the system of equations.
4x + 1 over 2y = -12
3x + 2y = 4
1 solutions
Answer 176810 by checkley77(7072) on 2009-11-21 17:17:39 (Show Source):
You can put this solution on YOUR website!4x + y/2 = -12 multiply this equation by -4 & add
3x + 2y = 4
-16x-2y=48
------------------
-13x=52
x=52/-13
x=-4 ans.
4*-4+y/2=-12
-16+y/2=-12
y/2=-12+16
y/2=4
y=2*4
y=8 ans.
Proof:
3*-4+2*8=4
-12+16=4
4=4
|
Linear-equations/241282: How do you write the slope-intercept form for the equation for the line passing through the given pair of points. (-5,1) and (4,6)
1 solutions
Answer 176743 by checkley77(7072) on 2009-11-21 10:43:24 (Show Source):
You can put this solution on YOUR website!(-5,1) and (4,6)
Slope=(6-1)/(4+5)
Slope=5/9 ans.
1=5/9*-5+b
1=-25/9+b
b=1+25/9
b=9/9+25/9
b=34/9 ans. for the y intercept.
Y=5x/9+34/9
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, 5x/9 +34/9).
|
Graphs/241347: Determine the solution to the system of linear equations graphically. If the system is dependent or inconsistent, so state.
3x + y = 8
12x + 4y = 32
1 solutions
Answer 176741 by checkley77(7072) on 2009-11-21 10:30:11 (Show Source):
You can put this solution on YOUR website!3x + y = 8
y=-3x+8 (red line)
12x + 4y = 32
4y=-12x+32
y=-12x/4+32/4
y=-3x+8 (green line)
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -3x +8 and -3x +8).
These equations are identical.
|
Equations/241343: Solve the problem. If necessary, round to the nearest tenth.
On a sunny day, a tree and its shadow form the sides of a right triangle. If the hypotenuse is 35 m long and the tree is 28 m tall, how long is the shadow?
1 solutions
Answer 176740 by checkley77(7072) on 2009-11-21 10:24:50 (Show Source):
|
Graphs/241349: Find the soultion to the system of equations.
x + 7y = -2
3x + y = 34
1 solutions
Answer 176737 by checkley77(7072) on 2009-11-21 10:19:02 (Show Source):
You can put this solution on YOUR website!x + 7y = -2 multiply by -3 & add
3x + y = 34
-3x-21y=6
--------------------
-20y=40
y=40/-20
y=-2 ans.
x+7*-2=-2
x-14=-2
x=-2+14
x=12 ans.
3*12-2=34
36-2=34
34=34
|
Radicals/241284: 1. 2x^2-x=-6
2. Factor c^2+14c+49=
3. (Use radical exponents to simplify) 4 radical x^12
4. Factor. 144c^2 + 648cf +729f^2=
5. Factor. 6x^7-18x^6+42x^5
1 solutions
Answer 176736 by checkley77(7072) on 2009-11-21 10:15:40 (Show Source):
You can put this solution on YOUR website!1. 2x^2-x=-6
2x^2-x+6=0
(2x+3)(x-2)=0
2x+3=0
2x=3
x=3/2 ans.
x-2=0
x=2 ans.
-----------------------------------
2. Factor c^2+14c+49
(c+7)^2 ans.
-------------------------------------
3. (Use radical exponents to simplify) 4 radical x^12
4*x^6=4x^6 ans.
---------------------------------------
4. Factor. 144c^2 + 648cf +729f^2=
(12c+27f)^2 ans.
------------------------------------
5. Factor. 6x^7-18x^6+42x^5
6x^5(x^2-3x+7)
|
Average/241286: Ryan scored 16, 22 and 24 points in three basketball games. What is the least number of points he must score in the next game to average at least 20 points per game for the four games?
1 solutions
Answer 176734 by checkley77(7072) on 2009-11-21 09:58:27 (Show Source):
You can put this solution on YOUR website!(16+22+24+x)/4>=20
(62+x)/4>=20
62+x>=4*20
x>=80-62
x>=18 points are needed in the 4th game to ave. 20 for the 4 games.
Proof:
(16+22+24+18)/4>=20
80/4>=20
20>=20
|
|
