Answer:
Tina's age = 2 years
Step-by-step explanation:
Tina's age = x
Michelle's age = 3 * x = 3x
Tina is 4 years younger than Michelle.
x = 3x - 4
Add 4 to both side
x +4 = 3x
Subtract x from both sides
4 = 3x - x
4 = 2x
Divide both sides by 2
4/2 = x
2 = x
Tina's age = 2 years