Question

Find the value of x.

Answer 1

`\huge\boxed{x=√(70)}`

Explanation:

ΔABC and ΔADB are similar (AAA).

Therefore the corresponging sides are in proportion:

`(AB)/(AD)=(AC)/(AB)`

Substitute:

`AB=x\\AC=7+3=10\\AD=7`

`(x)/(7)=(10)/(x)` cross multiply

`(x)(x)=(7)(10)\\\\x^2=70\to x=√(70)`