Answer:
Step-by-step explanation:
7 + 3 + 5 + 15 = 30
The answer is 21 + 4x.
You find this answer by adding up all the sides.
9+12+4x= 21+4x ... you don't add 4x because it has a variable that we do not know of the value.
The <em><u>correct answer</u></em> is:
624 crayons.
Explanation:
In 12 of the boxes, 28 crayons have not been used; this leaves 64-28=36 crayons that have been used. 12(36) = 432 crayons have been used in these boxes.
3 full boxes have been used; this is 3(64) = 192 crayons.
Together this makes 432+192 = 624 crayons that have been used.