How do you solve \frac { 1} { 2} ( 4x - 1) ^ { 2} = 412(4x1)2=4?

2 Answers
Jul 23, 2017

x=(+-sqrt(8)+1)/4x=±8+14

Explanation:

First, we remove the 1/212 by multiplying each side by 2 to get (4x-1)^2=8(4x1)2=8.

Then to remove the square, we square root each side to get 4x-1=+-sqrt(8)4x1=±8

We just need the4x4x on its own, so we add 1 to each side, 4x=+-sqrt(8)+14x=±8+1.

Now, to get xx on its own we divide both sides by 4, x=(+-sqrt(8)+1)/4x=±8+14

Jul 23, 2017

color(magenta)(x=1/4+(sqrt2)/2x=14+22 or x=0.957106781x=0.957106781

or

color(magenta)(x=1/4-sqrt2/2x=1422 or x=-0.457106781x=0.457106781

Explanation:

1/2(4x-1)^2=412(4x1)2=4

Multiply both sides by 2

:.(4x-1)^2=8

:.4x-1=sqrt8

:.4x=sqrt8+1

:.x=(sqrt8+1)/4

:.x=(sqrt(2*2*2)+1)/4

:.sqrt2*sqrt2=2

x=(2sqrt2+1)/4

x=1/4+(cancel2^1sqrt2)/cancel4^2

x=1/4+-sqrt2/2

color(magenta)(x=1/4+sqrt2/2 or x=0.957106781

color(magenta)(x=1/4-sqrt2/2 or x=-0.457106781