help me solve this plz..
y=x-7 and 2x+y=8
2007-09-05 12:58:04 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
y=x-7 and 2x+y=8
Substitute (x-7) for y in the second equation
2x + (x-7) = 8
3x - 7 = 8
3x = 15
x = 5
y = x-7
y = 5-7
y = -2
2007-09-05 13:04:22 · answer #1 · answered by Steve A 7 · 0⤊ 0⤋
second eq'n is y = 8 - 2x
double first: 2y = 2x - 14, and add: 3y = -6, so y = -2
and from first, x = 5
test this result: -2 = 5 - 7 ok
2*5 - 2 = 8 ok
2007-09-05 20:06:17 · answer #2 · answered by John V 6 · 0⤊ 0⤋
just plug in whatever equals y from the first equation into the second
2x+(x-7)=8
2x+x-7=8
3x=15
x=5
then plug the answer for x into the y equation
y=5-7
y=-2
2007-09-05 20:06:05 · answer #3 · answered by Whitney 2 · 0⤊ 0⤋
y=x-7 I am guessing you want to solve for x?
just add 7.
x=y+7
what are you solving for in the second one?
2007-09-05 20:04:44 · answer #4 · answered by computer whiz 5 · 0⤊ 0⤋