Answer:
x = -2 (verified by algebra) ✅
Step-by-step explanation:
Since we are given the value of y, we can replace it with 5x + 7.
We now have: 3x + 5x + 7 = -9
We can now simplify by adding 3x and 5x to get 8x.
8x + 7 = -9
We can subtract 7
8x = -16
And now, we divide by 8
x = -2
We can check to make sure we are correct
3(-2) + 5 (-2) + 7 = -9
-6 + -10 + 7 = -9
-9 = -9 ✅
