How do you simplify $5x^2 – 1 = 74$ ?

Question

1430 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-31T20:20:24

$x=±sqrt 15$

$5x^2-1=74$

$5x^2=74+1$

$cancel(5)x^2=cancel(75)$

$x^2=15$

$sqrt(x^2)=sqrt15$

$x=±sqrt 15$

Answer 2 · 2016-07-31T20:21:18

$x=+-sqrt(15)$

add 1 to both sides

$5x^2=75$

Divide both sides by 5

$x^2=15$

Square root both sides

$x=+-sqrt(15)$

How do you simplify 5x^2 – 1 = 745x^2 – 1 = 74?