Answer:
C
The "inverse operation" is just a way of saying "what do you do to isolate the variable". In this case, we isolate y, so we have to move all terms to the right side. To do that, we subtract 12 from each side to there will only be "y" on the left side.
3/4 x 12 = 9
The answer is 9
The anwser to your problem is 1,800
Algebra
Use the distributive property to make 5x+5.
5x+5<25
Subtract 5 from both sides.
5x<20
Divide both sides by five.
x<4