Someone help me out with this one

Step-by-step explanation:

AB + BC = AC

9x + 7  - 3x + 20 = 39    { combine like terms}

9x  -3x + 7 + 20 = 39

            6x + 27 = 39 {Subtract 27 from both sides}

                     6x = 39- 27

                      6x = 12   {divide both sides by 6}

                    6x/6 = 12/6

x = 2

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6