New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'checkley75'
checkley75 answered: 3664 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, >>NextLinear-equations/89539: Solve each of the following systems by substitution.
5x - 2y= -5
y - 5x = 3
8x - 4y = 16
y = 2x - 4
4x - 12y = 5
-x + 3y= -1
1 solutions
Answer 65081 by checkley75(3666) on 2007-07-22 20:34:38 (Show Source):
You can put this solution on YOUR website!Y-5X=3 OR Y=5X+3 NOW WE SUBSTITUTE (5X+3) FOR Y IN THE OTHER EQUATION & SOLVE FOR X:
5X-2(5X+3)=-5
5X-10X-6=-5
-5X=6-5
-5X=1
X=1/-5
X=-1/5 ANSWER.
Y-5*-1/5=3
Y+5/5=3
Y+1=3
Y=3-1
Y=2 ANSWER.
PROOF
5*-1/5-2*2=-5
-5/5-4=-5
-1-4=-5
-5=-5
I'LL LEAVE THE REST FOR YOU TO SOLVE USING THE SAME PROCEDURE!
|
Linear-equations/89540: A coffee merchant has coffee beans that sell for $9 per
pound and $12 per pound. The two types are to be mixed to create 100 lb of a mixture that will sell for $11.25 per pound. How much of each type of bean should be used in the mixture?
1 solutions
Answer 65079 by checkley75(3666) on 2007-07-22 20:28:24 (Show Source):
You can put this solution on YOUR website!9x+12(100-x)=100*11.25
9x+1200-12x=1125
-3x=1125-1200
-3x=-75
x=-75/-3
x=25 pounds of $9 coffee.
then we need 75 pounds of $12 coffee.
proof
9*25+12*75=100*11.25
225+900=1125
1125=1125
|
Surface-area/89445: The base of a rectangle is twice the side of a square, and the height of the rectangle is two more than the side of the square. The area of the rectangle is 32 square inch units more than the area of the square. Find the dimensions of the rectangle. 1 solutions
Answer 65028 by checkley75(3666) on 2007-07-22 08:45:24 (Show Source):
You can put this solution on YOUR website!THE SQUARE AREA =X^2
THE AREA OF THE RECTANGLE = 2X(X+2)
2X(X+2)-32=X^2
2X^2+4X-32=X^2
2X^2-X^2+4X-32=0
X^2+4X-32=0
(X-4)(X+8)=0
X-4=0
X=4 ANSWER FOR THE SIDES OF THE SQUARE.
SIDES OF THE RECTANGLE ARE 2*4=8 & 2(4+2)=2*8=16. THE SIDES OF THE RECTANGLE ARE 8 & 16.
PROOF
2*4(4+2)-32=4^4
8*6-32=16
48-32=16
16=16
|
Quadratic_Equations/89453: Please help me on how to figure out the y-intercept of the graph of the equation y=x2 (this is x squared) 6x = 9 and -3/2 (x-6)2 (squared). 1 solutions
Answer 65026 by checkley75(3666) on 2007-07-22 08:38:34 (Show Source):
You can put this solution on YOUR website!y=x^2 (red line)
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = x^2 ).
---------------------------------------------------------------------------
6x=9 or x=9/6 or x=1.5 this line has no y intercept. it is a verticle line passing through (1.5,0)
--------------------------------------------------------------------------
-3/2(x-6)^2 also has no y intercept
-3/2(x^2-12x+36) or -3x^2-18x-54 or -3(x^2+6x+18)
|
Linear_Equations_And_Systems_Word_Problems/89377: a) Set up an equation for the perimeter involving only L, the length of the rectangle. Suppose that the width of a rectangle is 5 inches shorter than the length and that the perimeter of the rectangle is 50.
b)Solve this equation algebraically to find the length of the rectangle. Find the width as well 1 solutions
Answer 65011 by checkley75(3666) on 2007-07-21 19:10:30 (Show Source):
You can put this solution on YOUR website!2L+2W=50 & W=L-5 THUS WE SUBSTITUTE (L-5) FOR W & SOLVE THE FIRST EQAUTION:
2L+2(L-5)=50
2L+2L-10=50
4L=50+10
4L=60
L=60/4
L=15 IS THE LENGTH OF THE RECTANGLE.
W=15-5
W=10
PROOF:
2*15+2*10=50
30+20=50
50=50
|
Polynomials-and-rational-expressions/89424: The formula N=t^2-t/2
describes the number of football games, N that must be played in a league with t teams if each team is to play every other team once.
How do I use the above to solve this problem below
If a league has 36 games scheduled, how many teams belong to the league,assuming that each team plays every other team once? The book says 9 how would I set it up in the formula above. 1 solutions
Answer 65010 by checkley75(3666) on 2007-07-21 19:04:22 (Show Source):
You can put this solution on YOUR website!36=T^2-T/2
T^2-T/2-36=0
USING THE QUADRATIC EQUATION WE GET (T=6.26 & -5.76)
SOLVING THIS EQUATION USING 9 AS THE NUMBER OF TEAMS (t) WE GET
N=9^2-9/2
N=81-4.5
N=76.5 THIS SAYS SOMETHING IS WRONG WITH YOUR EQUATION OR THE ANSWER 9 IS INCORRECT.
|
Mixture_Word_Problems/89411: Angela needs 20 quarts of 50% antifreeze solution in her radiator. She plans to obtain this by mixing some pure anitfreeze with an appropriate amount of a 40% solution. How many quarts of each should she use? 1 solutions
Answer 65009 by checkley75(3666) on 2007-07-21 18:51:15 (Show Source):
You can put this solution on YOUR website!.40X+(20-X)=.5*20
.4X+20-X=10
-.6X=10-20
-.6X=-10
X=-10/-.6
X=16.67 GALLONS OF 40% ANTIFREEZE IS REQUIRED.
THUS WE'LL NEED 3.33 GALLONS OF 100% ANTIFREEZE.
16.67*.4+3.33=10
6.67+3.33=10
10=10
|
Proportions/89413: tickets at a local movie were sold at $6.00 for adults and $4.50
for students. if 264 tickets were sold for a total of $1563.00, how many adults tickets were sold ? 1 solutions
Answer 65008 by checkley75(3666) on 2007-07-21 18:39:50 (Show Source):
You can put this solution on YOUR website!A+S=264 OR S=264-A
6A+4.5S=1563.
NOW SUBSTITUTE (264-A) FOR S IN THIS EQUATION & SOLVE FOR A:
6A+4.5(264-A)=1563
6A+1188-4.5A=1563
1.5A=1563-1188
1.5A=375
A=375/1.5
A=250 NUMBER OF ADULT TICKETS SOLD.
264-250=14 NUMBER OF STUDENT TICKETS SOLD.
PROOF
6*250+4.5*14=1563
1500+63=1563
1563=1563
|
Proportions/89414: maria purchased 12 pens and 8 notebooks for $15.00. bob bought 4 pens and 3 notebooks for $5.50. find the price of one pen and the price of one notebook ,agebraically. 1 solutions
Answer 65007 by checkley75(3666) on 2007-07-21 18:31:39 (Show Source):
You can put this solution on YOUR website!12P+8N=15.00
4P+3N=5.50 NOW MULTIPLY THE SECOND EQUATION BY -3 & ADD:
-12P-9N=-16.50
12P+8N=15.00
-----------------------------
-N=-1.50
N=1.50 PRICE OF THE NOTEBOOK.
12P+8*1.50=15.00
12P+12.00=1500
12P=15.00-12.00
12P=3.00
P=3.00/12
P=.25 COST OF THE PEN.
PROOF
4*.25+3*1.50=5.50
1.00+4.50=5.50
5.50=5.50
|
Linear-equations/89286: HOW DO YOU GRAPH
2y-y=4
2y-y=6
and
x-2y=8
3x-2y=12 1 solutions
Answer 64991 by checkley75(3666) on 2007-07-21 14:25:29 (Show Source):
You can put this solution on YOUR website!2y-y=4 or y=4 (red line)
2y-y=6 or y=6 (green line)
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = 4 and y = 6).
---------------------------------------------------------------------
x-2y=8 or -2y=-x+8 or y=-x/-2+8/-2 or y=x/2-4 (red line)
3x-2y=12 or -2y=-3x+12 or y=-3x/-2+12/-2 or y=3x/2-6 (green line)
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = x/2 -4 and y = 3x/2 -6).
|
Quadratic_Equations/89280: Find the x-intercepts.
y = x^2 – 3x – 1
1 solutions
Answer 64990 by checkley75(3666) on 2007-07-21 14:15:11 (Show Source):
You can put this solution on YOUR website!Y=X^2-3X-1
0=X^2-3X-1
USING THE QUADRATIC EQUATION:  WE GET:
X=(3+-SQRT{-3^2-4*1*-1])/2*1
X=(3+-SQRT9+4])/2
X=(3+-SQRT13)/2
X=(3+-3.6)/2
X=(3+3.6)/2
X=6.6/2
X=3.3 ANSWER.
X=(3-3.6)/2
X=-.6/2
X=-.3 ANSWER.
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = x^2 -3x -1).
|
Linear-equations/89398: y= 3 - 5/4x
graph this equation.what is the slope and y-intercept of the line?
then find the corresponding value of y when x = 16 by using the answer y= 3- 5/4x.
lost in translation? help would be soooooooooooo grateful 1 solutions
Answer 64981 by checkley75(3666) on 2007-07-21 13:35:20 (Show Source):
You can put this solution on YOUR website!Y=3-5/(4*16)
Y=3-5/64
Y=(3*64-5)/64
Y=(192-5)/64
Y=187/64
Y=2.921875 ANSWER. GRAPH FOLLOWS:
 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = -5/4x -3).
OR:
Y=3-(5/4)16
Y=3-5*16/4
Y=3-5*4
Y=3-20
Y=-17
|
Numbers_Word_Problems/89346: The cost in dollars of manufacturing w wing nuts is given by the expression 0.07w + 13.33. Find the cost when 375 wing nuts are made. What is the average cost to manufacture one wing nut? 1 solutions
Answer 64904 by checkley75(3666) on 2007-07-20 20:09:36 (Show Source):
|
Quadratic_Equations/89143: suppose that the width of a rectangle is 5 inches shorter than the length and that the perimeter of the rectangle is 50. set up an equation for the perimeter involving L, the length of the rectangle. then solve algebraically. 1 solutions
Answer 64862 by checkley75(3666) on 2007-07-20 11:05:50 (Show Source):
You can put this solution on YOUR website!W=L-5
2(L-5)+2L=50
2L-10+2L=50
4L=50+10
4L=60
L=60/4
L=15 ANSWER FOR THE LENGTH.
W=15-5
W-10 ANSWER FOR THE WIDTH.
PROOF
2*15+2*10=50
30+20=50
50=50
|
Quadratic_Equations/89235: Maria recently applied for a job in a computer store. The position is paid a base salary of $1875 a month plus a 6% commission on all sales over $5000 during the month. How much must she sell in 1 month to earn a total of $2783.00 for the month? 1 solutions
Answer 64854 by checkley75(3666) on 2007-07-20 10:47:26 (Show Source):
You can put this solution on YOUR website!2783-1875=$908 COMMISION EARNED.
.06X=908
X=908/.06
X=$15,133.33 AMOUNT NEEDED TO SELL ABOVE THE BASE OF $5,000
THE TOTAL AMOUNT OF SALES MUST BE $5,000+$15,133.33=$20,133.33 TOTAL AMOUNT OF SALES TO EARN A MONTHLY SALARY OF $2783.
|
Quadratic_Equations/89237: Suzy and Charolette are involved in a service project helping ederly neighbors fix up their yards for summer. If it takes Suzy 9 hours to do the job on her own, and it takes them 4 hours working together, how long will it take Charolette to fix up the yard by herself? 1 solutions
Answer 64851 by checkley75(3666) on 2007-07-20 10:40:51 (Show Source):
You can put this solution on YOUR website!9Y/(9+Y)=4 NOW CROSS MULTIPLY.
9Y=4(9+Y)
9Y=36+4Y
9Y-4Y=36
5Y=36
Y=36/5
Y=7.2 HOURS FOR CHARLOTTE TO DO THE JOB ALONE.
PROOF
9*7.2/(9+7.2)=4
64.8/16.2=4
4=4
|
|