How do you solve $4x^2-6=74$ ?

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Answer 1 · 2018-03-03T21:11:59

$x=2sqrt5$

We can begin by adding $6$ to both sides of this equation. Doing this, we get:

$4x^2=80$

We want to isolate $x$ , so the next best step would be to divide both sides by $4$ . We get:

$x^2=20$

Now, we can take the square root of both sides to get:

$x=+-sqrt20$ (We have a positive and negative answer because squaring a negative number will also result in a positive number)

We can factor out a perfect square from $+-sqrt20$ .
$20$ is equal to $4*5$ , so $sqrt20$ will be equal to $sqrt4*sqrt5$ . Now, we have:

$x=+-(color(blue)(sqrt4)*color(red)sqrt5)$

This simplifies to:

$x=+-color(blue)(2)color(red)sqrt5$

How do you solve 4x^2-6=744x^2-6=74?