Question

In the diagram below, ABC - DEC. What is the value of x? A 5 B. 3 C. 6 D. 4​

Answer 1

Answer:

C

Step-by-step explanation:

Since the triangles are similar then the ratios of corresponding sides are equal, that is

$\frac{BC}{EC}$ = $\frac{AC}{DC}$, substituting values

$\frac{21}{7}$ = $\frac{24-x}{x}$ ( cross- multiply )

21x = 7(24 - x) ← distribute

21x = 168 - 7x ( add 7x to both sides )

28x = 168 ( divide both sides by 28 )

x = 6 → C