If a=-3 what is 3a squared

 27

Work Shown:

a = -3

a^2 = (-3)^2 squaring both sides

a^2 = 9

3a^2 = 3*9 multiply both sides by 3

3a^2 = 27

Or you could do it this way

3a^2 = 3(-3)^2 ... replace 'a' with -3

3a^2 = 3(9)

3a^2 = 27

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.