How do you solve the system of equations 7x - 2y = - 337x2y=33 and 5x + 4y = 95x+4y=9 by elimination?

1 Answer
Mar 22, 2017

x=-3x=3
y=6y=6

Explanation:

7x-2y=-337x2y=33 -----------------------(1)
5x+4y=95x+4y=9 ------------------------(2)

Multiply equation (1) with 2

7x-2y=-337x2y=33 -----------------------(1) xx 2×2

14x-4y=-6614x4y=66 ----------------------(3)
5x+4y=95x+4y=9 ------------------------(2) ---(3)+(2)(3)+(2)
19x=-5719x=57
x=(-57)/19=-3x=5719=3

x=-3x=3

Substitute x=-3x=3 in equation (1)

7(-3)-2y=-337(3)2y=33
-21-2y=-33212y=33
-2y=-33+21=-122y=33+21=12
y=(-12)/(-2)=6y=122=6
y=6y=6