Question

Solve, using the substitution method.

5x + 2y = 7
y = x – 7


A. (7, 0)
B.(3, –4)
C, (0, –7)
D.(–1, –8)

Answer 1

5x+2y=7
y=x-7

5x=7-2y
5x=7-2(x-7)
5x=7-2x+14
5x+2x=7+14
7x/7=21/7
x=3

y=x-7
y=3-7
y=-4

Answer is B