Solve the following system of equations.
-6x + 10y = 5
-2x + 3y = -1
a. x = 11 1/2, y = 8
b. x = 25/38, y = 2/19
c. x = 12 1/2, y = 8
d. x = 13/38, y = 2/19
2006-10-10 10:29:55 · 8 answers · asked by JoAnna 2 in Science & Mathematics ➔ Mathematics
Hi JoAnna
-6x + 10y = 5
-2x + 3y = -1
Step 1
multiply the second function by ' - 3 '
- 3 * (-2x + 3y = -1)
+ 6x - 9y = +3
Step 2
add them
-6x + 10y = 5
+ 6x - 9y = +3
____________
0 + y = 8
y = 8
Step 3
fill the value of y in to one of the functions ;
-2x + 3y = -1
y = 8
-2x + 3(8) = -1
-2x + 24 = -1
-2x = -1 - 24
-2x = -25
x = ( -25/ -2)
x = 12.5 OR 12 1/2
So the answer is
Part c
c. x = 12 1/2, y = 8
Good Luck darling.
2006-10-10 10:44:40 · answer #1 · answered by sweetie 5 · 7⤊ 1⤋
c. x = 12 1/2, y = 8
Original equations:
-6x + 10y = 5
-2x + 3y = -1
Now multiply the second equation by 3 to get the same coefficient on x:
-6x + 10y = 5
-6x + 9y = -3
Subtract the second from the first:
y = 8
Plug that back into one of the original equations:
-2x + 3(8) = -1
-2x + 24 = -1
2x = 25
x = 25/2
c. x = 12 1/2, y = 8
2006-10-10 17:33:20 · answer #2 · answered by Puzzling 7 · 1⤊ 0⤋
Multiply the second equation by 3:
-6x + 10y = 5
-6x + 9y = -3
Subtract the second equation from the first:
y = 8
Plug this value of y into either equation, and solve for x to get x = 12 1/2.
2006-10-10 17:35:28 · answer #3 · answered by James L 5 · 0⤊ 0⤋
-6x + 10y = 5
-2x + 3y = -1
Multiply the second equation by 3 all the way across: -6x +9y =-3
Then subtract this new equation from the first equation:
You get:
-6x + 10y - -6x - 9y = 5 - -3
Simplify
y = 8
Substituting y=8 into the second equation gives:
-2x + 3(8) = -1
-2x + 24 = -1
-2x = -25
x = 25/2 or 12 1/2
The correct answer is c.
2006-10-10 17:35:03 · answer #4 · answered by Draco Moonbeam 3 · 0⤊ 0⤋
-6x+10y=5
-2x+3y=-1 Multiply the second equation by 3 -6x+9y=-3 Subtract the 3rd equation from the1st y=8 Substitute 8 for y in the 1st -6x +80=5 -6x=-75 x=12.5
2006-10-10 17:50:23 · answer #5 · answered by Anonymous · 0⤊ 0⤋
subtract 3*2nd equation from 1st
-6x+ 10y= 5
6x - 9y= 3
we get y =8
substitute value of y in 2nd equation
-2x +24 = -1
-2x =-25
x=12 1/2
solution is [c] x= 12 1/2 ; y=8
2006-10-10 17:44:21 · answer #6 · answered by Anonymous · 0⤊ 0⤋
x = 1/2 + 3/2 y
-6(1/2 + 3/2 y) + 10y =5
-3 +y=5
y= 8
x = 12 1/2
(c)
2006-10-10 17:39:42 · answer #7 · answered by Steve P 5 · 0⤊ 0⤋
a.-6x + 10y = 5
b. -2x + 3y = -1
Solve:
3(-2x + 3y = -1) --> -6x+9y=-3
Subtract:
-6x + 10y = 5
-6x + 9y = -3
___________
y=8
Subsitute y=8 with any equation
-6x+10(6)=5
x=12.5
Therefore the ans is C.
2006-10-10 17:35:10 · answer #8 · answered by Cherry 1 · 0⤊ 0⤋