Question

what is the value of x? enter your answer in the box. x =
40 cm
5 cm
3 cm
2x + 10

Explanation:

Step1: Use similar - triangle property

Since the two triangles are similar, the ratios of their corresponding sides are equal. So, $\frac{40}{2x + 10}=\frac{5}{3}$.

Step2: Cross - multiply

Cross - multiplying the proportion $\frac{40}{2x + 10}=\frac{5}{3}$ gives us $40\times3 = 5\times(2x + 10)$.

Step3: Simplify the equation

$120=10x + 50$.

Step4: Isolate the variable term

Subtract 50 from both sides: $120−50 = 10x$, so $70 = 10x$.

Step5: Solve for x

Divide both sides by 10: $x=\frac{70}{10}=7$.

Answer:

$7$