inequality

0.75x>3

Multiply both sides of the inequality by 4/3 if you want to know what x is.

from where did you get 4/3 to multiply to find x. How do you know that?

MULTIPLY BOTH SIDES BY 4/3

The 4/3 comes from dividing both sides of the equation by 0.75 or 3/4. To divide by a fraction means to multiply by its reciprocal. Hence, to divide each side by 3/4 (0.75) means to multiply by 4/3 which is the reciprocal.