How do you use the quadratic formula to solve $3.8x^2=4.7x-2.1$ ?

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Answer 1 · 2017-09-29T12:26:29

See a solution process below:

First, rewrite the equation as:

$3.8x^2 - color(red)(4.7x) + color(blue)(2.1) = 4.7x - color(red)(4.7x) - 2.1 + color(blue)(2.1)$

$3.8x^2 - 4.7x + 2.1 = 0 - 0$

$3.8x^2 - 4.7x + 2.1 = 0$

Now, we can 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:

$color(red)(3.8)$ for $color(red)(a)$

$color(blue)(-4.7)$ for $color(blue)(b)$

$color(green)(2.1)$ for $color(green)(c)$ gives:

$x = (-color(blue)((-4.7)) +- sqrt(color(blue)((-4.7))^2 - (4 * color(red)(3.8) * color(green)(2.1))))/(2 * color(red)(3.8))$

$x = (4.7 +- sqrt(22.09 - 31.92))/7.6$

$x = (4.7 +- sqrt(-9.83))/7.6$

How do you use the quadratic formula to solve 3.8x^2=4.7x-2.13.8x^2=4.7x-2.1?