Question

Solve the following system of equations using the

substitution method:
y = x2 + 3x - 12
y = x + 3

Answer 1

y = x² + 3x - 12

y = x + 3

Substitute the second value of y into the first equation, and you'll have

x + 3 = x² + 3x - 12

Now solve

0 = x² + 2x - 15

0 = (x + 5)(x - 3)

x = - 5, x = 3

With -5, you'll get y = - 2

With 3, you'll get y = 6

Answer 2

The solutions are 3 and -5

Explanation:

x+3=x^2+3x-12

x^2+2x-15

=(x-3)(x+5)