How do I answer 3(a - 5) = 18

To solve this, you need to isolate/get the variable "a" by itself in the equation:

3(a - 5) = 18          Divide 3 on both sides

a - 5 = 6          Add 5 on both sides to get "a" by itself

a - 5 + 5 = 6 + 5

a = 11

PROOF

3(a - 5) = 18      Substitute/plug in 11 into "a" since z = 11

3(11 - 5) = 18

3(6) = 18

18 = 18

i would say c is the best answer, hope it's right!

good luck! =)

cutie~