2x-y+=-9

3x-8y=-7
using the substitution method.

2 answers

What's the answer?

for this

Georgette has n books. Jackie has half as many books. How many books does jackie have?
from the first equation,

y = 2x+9 (ignoring the spurious + sign)

substituting that into the second equation,

3x - 8(2x+9) = -7
3x - 16x - 72 = -7
-13x = 65
x = -5
so, y = -1