the equation for the stated problem would be:
3x ≥ -6
Assuming you are focusing on the square only, then the answer is 9 inches.
You take the square root of 81 to get 9. Notice how 9^2 = 9*9 = 81. So if you're not familiar with square roots, then think backwards in a sense to get the answer.
2/3 is the same 4/6
7/2 is the same as 21/6
4/6 + 21/6 = 25/6
So the answer is 25/6, not 25/5.
2(wl+hl+hw)=2·(14·2+11·2+11·14)=408