Question

Solve the equation. Check for extraneous solutions. 2[7-7x]=2x+4

A. x =3/2 or x = 5/6
B. x =3/2 or x =5/8
C. x = 5/8
D. x = 3/2

Answer 1

To solve this problem you must apply the proccedure shown below:

1. You have the following expression:

`2[7-7x]=2x+4`

2. To solve it, you must solve for the variable
`x`, as following:

`14-14x=2x+4 \\ x= (10)/(16) \\ x= (5)/(8)`

3. Checking for extraneous solutions:

`x= (5)/(8) \\ 2[7-7( (5)/(8)) ]=2 ((5)/(8)) +4 \\ (21)/(4) = (21)/(4)`

`(5)/(8)` is a solution.

The answer is the option C:
`x=(5)/(8)`