9
algebra

A trapezoid has a perimeter of 40. The sides are 2x2x, 2x2x, 3x3x, and 1212. What is xx?

A

4

B

3

C

5

D

7

Correct Answer: A

Choice Choice A is the correct answer.

  1. Equation: 2x+2x+3x+12=402x + 2x + 3x + 12 = 40
  2. Combine: 7x+12=407x + 12 = 40
  3. Subtract 12: 7x=287x = 28
  4. Divide by 7: x=4x = 4
  5. Verify: 8+8+12+12=408 + 8 + 12 + 12 = 40

Choice Choice D is incorrect because calculation error.

Choice Choice C is incorrect because calculation error.

Choice Choice B is incorrect because calculation error.