-21+4x+x^2=0

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



-21+4x+x^2=0

a = 1; b = 4; c = -21;
Δ = b2-4ac
Δ = 42-4·1·(-21)
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$


$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-10}{2*1}=\frac{-14}{2}
=-7
$


$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+10}{2*1}=\frac{6}{2}
=3
$

See similar equations:

| 6x+8=10x-(+2) | | 2x-6÷4=-12 | | 3/4*x=-96 | | (3/4)x=-96 | | 3^2x-3^x=72 | | (-18)-6x=6(1+3x) | | 12/20=x/100 | | x/8=-104 | | -12=-(2x+8) | | (-4)x=12 | | (-15)(2x-4)=48 | | N+3-6n=8 | | .33x-6=4 | | 0.50b=400 | | x(3)=3x2–7 | | -9g=-63 | | x-49=114 | | 8(x+4)-6=-4(x+1) | | (x-13)*(x+8)=196 | | x(6)=12–4 | | 10y+11y-6y=0 | | -13x+11x-19=12x-31 | | 7a=301 | | 218=116-u | | 218=116u | | 5r-6=3-4r | | 7x=5-5x | | 6y-9y-4=-2 | | 3x-33=-9(x+5) | | 6x^2-11x-30=0 | | X+30=400-4x | | -15x+19=15x-10 |

Equations solver categories