8=4x-3y
17=x+3y
-6=3x+y
10=-5x-y
3x+8y=-1
-3x+y=-17
7x-y=12
-3y=7x+8
2007-09-24 14:29:57 · 4 answers · asked by ALESANA 7 in Education & Reference ➔ Homework Help
You only get one answer for 10 points.
8=4x-3y
17=x+3y
Add together to eliminate y:
25 = 5x, x = 5
Substitute for x in first equation:
8 = 4(5) - 3y
3y = 20 - 8, or 12
y = 4
Proof:
Substitute x & y values in 2nd equation:
17 = 5 + 3(4)
17 = 17
Both sides match
2007-09-24 14:40:29 · answer #1 · answered by Robert S 7 · 0⤊ 0⤋
If 4x - 3y = 8 Then, 4x = 8 + 3y => x = 2 + 3y/4
Plug the value of x in the second equation:
2 + 3y/4 + 3y = 17
15y/4 = 15
15y = 60
y = 4
Then plug the value of y in one of the equations:
4x - 3.4 = 8
4x - 12 = 8
4x = 20
x = 5
This is way you do it. Continue the rest.
Good luck,
2007-09-24 21:37:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
you need to solve for a variable. pick either x or y and try to solve for that one.
2007-09-24 21:33:17 · answer #3 · answered by Kristen 1 · 0⤊ 0⤋
you can solve that through elimination.
2007-09-24 21:33:55 · answer #4 · answered by not_a_geek 3 · 1⤊ 0⤋