Answer: x = 21 and x = 20
Explanation:
To solve for x in both of these equations, we can cross-multiply and isolate the variable.

Given:

Cross-multiply:
3 * x = 9 * 7
3x = 63
Divide both sides of the equation by 3:
x = 21

Given:

Cross-multiply:
5 * x = 8 * 12.5
5x = 100
Divide both sides of the equation by 5:
x = 20