Answer:
x = -2.
y = 3.
Step-by-step explanation:
If y = 3x + 9
Substitute this value for y in the first equation.
4x + 5(3x + 9) = 7
4x + 15x + 45 = 7
19x = 7 - 45
19x = -38
x = -38/19
x = -2.
with this value of x, substitute -2 in the second equation
y = 3(-2) + 9
y = -6+9
y = 3.
check if your values are all correct
4(-2) + 5(3) = 7
-8 + 15 = 15 - 8 = 7
Correct!
