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

1 Answer
Nallasivam V
Mar 22, 2017

x=-3x=−3
y=6y=6

Explanation:

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

Multiply equation (1) with 2

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

14x-4y=-6614x−4y=−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=-33−21−2y=−33
-2y=-33+21=-12−2y=−33+21=−12
y=(-12)/(-2)=6y=−12−2=6
y=6y=6

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