Question

Please help I don't understand!

Answer 1

Answer:

9

Step-by-step explanation:

Take the sides in proportion.

⇒ $\frac{AE}{AD} =\frac{AB}{AC}$

⇒ $\frac{12}{12+8} =\frac{x}{15}$

⇒ $\frac{12}{20} =\frac{x}{15}$

⇒ $\frac{3}{5} =\frac{x}{15}$

⇒ $3 = \frac{x}{3}$

⇒ x = 3 × 3

⇒ x = 9