Question

Which equation is equivalent to 3[x + 3(4x – 5)] = 15x – 24?15x – 15 = 15x – 2415x – 5 = 15x – 2439x – 45 = 15x – 2439x – 15 = 15x – 24?

Answer 1

Begin inside the brackets always.  Your first simplification will be to distribute the 3 into the parenthesis, resulting in this: $3[x+12x-15]=15x-24$.  We can simplify a bit more now inside the brackets like this: $3[13x-15]=15x-24$.  Now distribute the 3 to get 39x - 45 = 15x - 24.  That's your answer. The third one out of the 4 you have there.