### Home > PC > Chapter 6 > Lesson 6.4.2 > Problem6-157

6-157.

Solve for $x$.

1. $2x^2 − 5 = 2x$

Use the Quadratic Formula.

1. $6x^4 = x^2 + 5$

1. Bring all terms to the left side and set $= 0$.
2. Factor.

1. $\sqrt { x + 21 } + \sqrt { x }= 7$

1. Subtract the $\sqrt{x}$  from both sides.

2. Square both sides, multiplying out the right side.

1. $2 +\frac { 5 } { x - 1 } = \frac { 12 } { ( x - 1 ) ^ { 2 } }$

Multiply all terms by $(x − 1)^2$.