-x^2+4*x+21=0

Simple and best practice solution for -x^2+4*x+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 -x^2+4*x+21=0 equation:


Simplifying
-1x2 + 4x + 21 = 0

Reorder the terms:
21 + 4x + -1x2 = 0

Solving
21 + 4x + -1x2 = 0

Solving for variable 'x'.

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

Subproblem 1

Set the factor '(7 + -1x)' equal to zero and attempt to solve: Simplifying 7 + -1x = 0 Solving 7 + -1x = 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 + -1x = 0 + -7 Combine like terms: 7 + -7 = 0 0 + -1x = 0 + -7 -1x = 0 + -7 Combine like terms: 0 + -7 = -7 -1x = -7 Divide each side by '-1'. x = 7 Simplifying x = 7

Subproblem 2

Set the factor '(3 + x)' equal to zero and attempt to solve: Simplifying 3 + x = 0 Solving 3 + x = 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 + x = 0 + -3 Combine like terms: 3 + -3 = 0 0 + x = 0 + -3 x = 0 + -3 Combine like terms: 0 + -3 = -3 x = -3 Simplifying x = -3

Solution

x = {7, -3}

See similar equations:

| x+45x=180 | | y+5x=4+7x | | 18x-5x+2=-(x-3)-1 | | Y=6.25x | | x^2+4x-5.5=0 | | 2x-2=6-2x | | Y/3-6=-11 | | 6x+2=4x+11 | | 18y+7=13 | | 7(x-2)-5=30 | | (x-7)(x+9)=0findx | | 3a+14=20 | | x+(x-10)=60 | | 9(x^2-6)=0 | | 7m+26=(-29)-36m | | 2w+10=-2(w-9) | | y-8=-1/2(x-3) | | 7h-19=37 | | 10m-13=67 | | m*2=15 | | 10m-13=64 | | 3x+4=6x+2-(3x-2) | | -[3z-(7z+9)]=9+(3z+8) | | (4ln)x-6=0 | | y-10=(x-11) | | 7y-5=18 | | 5tan^2x-15=0 | | 22/r=36 | | 7h+6=66 | | 3t^2-13t-10= | | C-X(X-7)=0 | | 4x^2-16x+9= |

Equations solver categories