Question

Find the value of x.

Answer 1

`\large\boxed{x=10}`

Explanation:

Look at the picture.

ΔABC and ΔDBE are similar. Therefore the sides are in ptoportion:

`(AB)/(DB)=(AC)/(DE)`

We have

`AB=2y\\DB=y\\AC=3x\\DE=x+5`

Substitute:

`(2y)/(y)=(3x)/(x+5)`

`(2)/(1)=(3x)/(x+5)` cross multiply

`(2)(x+5)=(3x)(1)` use distributive property

`2x+10=3x` subtract 2x from both sides

`10=x\to x=10`