How do you solve x^2 +3x-10=0?

1 Answer
Oct 22, 2017

See a solution process below:

Explanation:

One solution is to factor the quadratic as:

(x - 2)(x + 5) = 0

Now, we can solve each term on the left for 0 to find the solutions:

Solution 1:

x - 2 = 0

x - 2 + color(red)(2) = 0 + color(red)(2)

x - 0 = 2

x = 2

Solution 2:

x + 5 = 0

x + 5 - color(red)(5) = 0 - color(red)(5)

x + 0 = -5

x = -5

he Solutions Are: x = 2 and x = -5

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

The quadratic formula states:

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)(1) for color(red)(a)

color(blue)(3) for color(blue)(b)

color(green)(-10) for color(green)(c) gives:

x = (-color(blue)(3) +- sqrt(color(blue)(3)^2 - (4 * color(red)(1) * color(green)(-10))))/(2 * color(red)(1))

x = (-color(blue)(3) +- sqrt(9 - (-40)))/2

x = (-color(blue)(3) +- sqrt(9 + 40))/2

x = (-color(blue)(3) - sqrt(9 + 40))/2 and x = (-color(blue)(3) + sqrt(9 + 40))/2

x = (-color(blue)(3) - sqrt(49))/2 and x = (-color(blue)(3) + sqrt(49))/2

x = (-color(blue)(3) - 7)/2 and x = (-color(blue)(3) + 7)/2

x = -10/2 and x = 4/2

x = -5 and x = 2