Step-by-step explanation
We must solve for x the following equation:

1) We multiply both sides by 4, and we get:

2) We pass the -16 at the left side as +16 at the right side:

3) We pass the -56 at the right side as +56 at the left side:

4) Finally, dividing both sides by 16, we get:

Answer
x = -3.5