Question

Solve the system of equations using subtraction.

3y = -1/2x + 2
Y= -x + 9

A. (10,-1)
B. (-1, 8)
C. ( 20,-4)
D. (3,6)

Answer 1

Mult the first eqn by -2, obtaining -6y = x - 4.

Combine this result with the 2nd equation:

-6y = x - 4
Y= -x + 9
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-5y = 5, so y = -1. Subbing this result for y into the 2nd eqn, we get
-1 = -x + 9, or -x = -10, or x = 10.

the solution is then (10, -1).