Question

Which of the following expressions is equivalent to 3x + 3x + 5 + 5?

1.) 3( x + 10)
2.) 2(6 x + 10)
3.) 3( x + 5)
4.) 2(3 x + 5)
this is multiple choice

Answer 1

The answer is 4. 2(3x+5)

Answer 2

Your answer is 4.) 2(3x +5)

When you collect like-terms in 3x + 3x + 5 + 5, you end up with 6x + 10 (because 3x + 3x = 6x and 5 + 5 = 10), so therefore you're looking for an answer that expands to give 6x + 10.

We can immediately rule out 2.) 2(6x + 10), because this is 2 times the correct answer, so it must expand to 12x + 20 instead of 6x + 10.

1.) 3(x + 10) expands to 3x + 30, so this is incorrect, and 3.) 3(x + 5) expands to 3x + 15, which is also wrong.

Therefore the answer is 4.) 2(3x + 5) which expands to 6x + 10.

I hope this helps! Let me know if you have any questions :)