Question

What is the value of x? Enter your answer in the box. x =

Answer 1

Answer:

x=9

Step-by-step explanation:

We can use similar triangles and proportions to solve.  Put the side of the small triangle over the side of the large triangle

9               3x-20

---------- = -----------------

9+72          3x-20 +56

Combine like terms

9               3x-20

---------- = -----------------

81             3x+36

Using cross products

9*(3x+36) = 81*(3x-20)

Distribute

27x + 324 = 243x- 1620

Subtract 27x from each side

27x-27x +324 = 243x-27x -1620

324 = 216x -1620

Add 1620 to each side

324+1620 = 216x-1620+1620

1944 = 216x

Divide by 216

1944/216 = 216x/216

9 = x

Answer 2

9 is the value of x. Hope this helps!