Question

△abc is similar to △edc. solve for x. 3x + 12 60 40 140

Explanation:

Step1: Set up proportion

Since $\triangle ABC\sim\triangle EDC$, the ratios of corresponding sides are equal. So, $\frac{3x + 12}{60}=\frac{140}{40}$.

Step2: Cross - multiply

$(3x + 12)\times40=60\times140$.
Expand the left - hand side: $120x+480 = 8400$.

Step3: Isolate the variable term

Subtract 480 from both sides: $120x=8400 - 480$, so $120x=7920$.

Step4: Solve for x

Divide both sides by 120: $x=\frac{7920}{120}=66$.

Answer:

$x = 66$