Answer:
9
Step-by-step explanation:
The mid line of a triangle is always half of the triangle's "base"
Plug all the answer choices in and see if they produce a true answer
20 = (2(10) - 8) * 2
20 = (20 - 8) * 2
20 = 12 * 2
20 ≠ 24
10 is NOT x
20 = (2(11) - 8) * 2
20 = (22 - 8) * 2
20 = 14 * 2
20 ≠ 28
11 is NOT x
20 = (2(14) - 8) * 2
20 = (28 - 8) * 2
20 = 20 * 2
20 ≠ 40
14 is NOT x
20 = (2(9) - 8) * 2
20 = (18 - 8) * 2
20 = 10 * 2
20 = 20
9 IS x!!!
Or you can do it this way:
20 = (2x - 8) * 2
Divide 2 to both sides
10 = 2x - 8
18 = 2x
x = 9
Hope this helped!
