Need help with this problem

Answer:
x = 10
Step-by-step explanation:
Since the triangles are similar the ratios of corresponding sides are equal
[tex]\frac{20}{20+8}[/tex] = [tex]\frac{3x}{4x+2}[/tex], that is
[tex]\frac{20}{28}[/tex] = [tex]\frac{3x}{4x+2}[/tex] ( cross- multiply )
20(4x + 2) = 84x
80x + 40 = 84x ( subtract 80x from both sides )
40 = 4x ( divide both sides by 4 )
x = 10