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