4y - x = 10
3y + 5x = -4
a)(2,2)
b)(2,-2)
c)(-2,-2)
d)(-2,2)
2007-11-05 00:08:51 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x = 4y - 10
3y + 5 (4y - 10) = -4
23 y = 46
y = 2
x = -2
Answer: D
2007-11-05 00:15:12 · answer #1 · answered by ? 6 · 0⤊ 0⤋
Using substtution
-x=10-4y
-x/-1=10-4y/-1
x=4y-10
3y+5(4y-10)=-4
3y+20y-50=-4
23y=46
y=2
4(2)-x=10
8-x=10
8-(-2)=10
8+2=10
therefore if y=2 then x =-2 b
2007-11-05 08:57:23 · answer #2 · answered by Dave aka Spider Monkey 7 · 0⤊ 0⤋
rearrange equation 1 to solve for x: 4y-10=x. Rearrange equation 2 to solve for x: x=(-4-3y)/5, equate the two: 4y-10=(-4-3y)/5, solve for y: y=2, substitute back into either equation (I picked the first): x=2*4-10=-2,
So the answer is d) (-2, 2).
2007-11-05 08:19:45 · answer #3 · answered by Scott 3 · 0⤊ 0⤋
multiply #1 by 5
20y=5x=50
3y +5x=-4
23y=46
y=2
substitute
4*2 -x =10
-x=2
x=-2
(-2,2)
2007-11-05 08:17:38 · answer #4 · answered by mom 7 · 0⤊ 0⤋
use eq1
x=4y-10 substitute into eq2
3y+5(4y-10)=-4
3y+20y-50=-4
23y=46
y=2
x=-2
answer is d
2007-11-05 08:16:25 · answer #5 · answered by someone else 7 · 0⤊ 0⤋
-x=10-4y
x=4y-10
3y+5(4y-10)=-4
3y+20y-50=-4
23y=46
y=2
x=8-10=-2
-2,2--------->option d
Hope this helps
2007-11-05 08:32:03 · answer #6 · answered by fiboway 2 · 0⤊ 0⤋
Its option (d)
2007-11-05 08:15:48 · answer #7 · answered by Pramod Kumar 7 · 0⤊ 0⤋