Question

Use elimination to solve the system of equations.

10x + 5y = 55
y - 2x = -9
A. (1,1)
B. (1,5)
C. (5, 1)
D. (4,5)

Answer 1

C. (5,1)

Explanation:

10x+5y=55 equation 1

y-2x=-9 equation 2

y=-9+2x isolate y in equation 2

10x+5(-9+2x)=55 substitute value of y from equation 2 into equation 1

10x-45+10x=55

20x=100

x=5

solve for y by using x value (5) in either equation

y-2x=-9

y-2(5)=-9

y-10=-9

y=1