How do you simplify sqrt( 8 x + 1) = 5?

2 Answers
Veddesh phi
Apr 9, 2016

x=3

Explanation:

color(blue)(sqrt( 8 x + 1) = 5

Square both sides to get rid of the radical sign

rarr(sqrt( 8 x + 1))^2 = 5^2

rarr8x+1=25

rarr8x=25-1

rarr8x=24

color(green)(rArrx=24/8=3

Check

color(brown)(sqrt( 8(3) + 1) = 5

color(brown)(sqrt(24+1)=5

color(brown)(sqrt25=5

color(green)(5=5

Tony B
Apr 9, 2016

x=3

Explanation:

Square root is an 'action'. To 'get rid' of that action you reverse it!

The reverse of square root is to square it.

Square both sides giving:

(sqrt(8x+1))^2=5^2

=>8x+1=25

Subtract 1 from both sides (the revers of add is subtract)

8x+1-1=25-1

8x=24

Divide both sides by 8 (the reverse of multiply is divide).

8/8xx x= 24/8

But 8/8=1

x=3

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