-5x^2+8x+21=0

Simple and best practice solution for -5x^2+8x+21=0 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for -5x^2+8x+21=0 equation:


Simplifying
-5x2 + 8x + 21 = 0

Reorder the terms:
21 + 8x + -5x2 = 0

Solving
21 + 8x + -5x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(3 + -1x)(7 + 5x) = 0

Subproblem 1

Set the factor '(3 + -1x)' equal to zero and attempt to solve: Simplifying 3 + -1x = 0 Solving 3 + -1x = 0 Move all terms containing x to the left, all other terms to the right. Add '-3' to each side of the equation. 3 + -3 + -1x = 0 + -3 Combine like terms: 3 + -3 = 0 0 + -1x = 0 + -3 -1x = 0 + -3 Combine like terms: 0 + -3 = -3 -1x = -3 Divide each side by '-1'. x = 3 Simplifying x = 3

Subproblem 2

Set the factor '(7 + 5x)' equal to zero and attempt to solve: Simplifying 7 + 5x = 0 Solving 7 + 5x = 0 Move all terms containing x to the left, all other terms to the right. Add '-7' to each side of the equation. 7 + -7 + 5x = 0 + -7 Combine like terms: 7 + -7 = 0 0 + 5x = 0 + -7 5x = 0 + -7 Combine like terms: 0 + -7 = -7 5x = -7 Divide each side by '5'. x = -1.4 Simplifying x = -1.4

Solution

x = {3, -1.4}

See similar equations:

| 32x^2-20x-25=0 | | 50-x^2=0 | | 338-6x^2=0 | | 5(x-3)+4-2x=52 | | x^3+6x^2+12x+8=0 | | -16x^2-10x+378=0 | | 2x^2-10=0 | | 2x^2+8=0 | | 15y+21+10=61 | | 3(2x+7)=10 | | =(4+4)*5+19-8+7+5*(7+1*10)+6 | | 2a+3+2a=11 | | 8x-4=3x+6 | | 4x+8=2x+14 | | 0.75(2y-8)=6 | | 12=x-8 | | 2(5-x)=5(x+7) | | 3x+2y-p=12 | | 25=x+10 | | x+2=6x-8 | | x^2-3x-88=0 | | (4+4)*5+19-8+7+5*(7+1*10)+6= | | 2x^2*29x*65=0 | | 2x+5=5x+11 | | 46-6x=4 | | x+131=125 | | 4d-3-2d=-15 | | -7(n+3)+24=-4n-15 | | 345+115x=255+130x | | 13y+12=7y+36 | | x^2-x=42 | | 15x+4-10x=5 |

Equations solver categories