Answer: x = 7
`Step-by-step explanation:
Because the figure shows two triangles that are similar. we can write and solve an equation of ratios:
9 cm 72 cm
----------- = -----------
3x - 20 56 cm
Cross-multiplying, we get (3x - 20)(72 cm) = (9 cm)(56 cm) = 504 cm²
Dividing both sides by 72 cm, we get:
3x - 20 = (504 cm²) / (72 cm) = 7
Then 3x - 20 = 7, and 3x = 27. Then x must be 9.
