How do you solve $4x^2=9x$ using the quadratic formula?

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Answer 1 · 2017-08-21T21:06:35

See a solution process below:

First, rewrite the equation as:

$4x^2 - 9x + 0 = 0$

We can now use the quadratic equation to solve this problem:

For $color(red)(a)x^2 + color(blue)(b)x + color(green)(c) = 0$ , the values of $x$ which are the solutions to the equation are given by:

$x = (-color(blue)(b) +- sqrt(color(blue)(b)^2 - (4color(red)(a)color(green)(c))))/(2 * color(red)(a))$

Substituting:

$color(red)(4)$ for $color(red)(a)$

$color(blue)(-9)$ for $color(blue)(b)$

$color(green)(0)$ for $color(green)(c)$ gives:

$x = (-color(blue)((-9)) +- sqrt(color(blue)((-9))^2 - (4 * color(red)(4) * color(green)(0))))/(2 * color(red)(4))$

$x = (9 +- sqrt(81 - 0))/8$

$x = (9 +- sqrt(81))/8$

$x = (9 - 9)/8$ and $x = (9 + 9)/8$

$x = 0/8$ and $x = 18/8$

$x = 0$ and $x = 9/4$

How do you solve 4x^2=9x4x^2=9x using the quadratic formula?