21a2+42a=-21

Simple and best practice solution for 21a2+42a=-21 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 21a2+42a=-21 equation: 



21a^2+42a=-21

We move all terms to the left:

21a^2+42a-(-21)=0

We add all the numbers together, and all the variables

21a^2+42a+21=0

a = 21; b = 42; c = +21;
Δ = b2-4ac
Δ = 422-4·21·21
Δ = 0
Delta is equal to zero, so there is only one solution to the equation

                              Stosujemy wzór:
$a=\frac{-b}{2a}=\frac{-42}{42}=-1$

See similar equations:

| 1x=5+6+7 | | 2x2=-3x=0 | | 2n2+5n-3=0 | | (x+2)(x+6)(x+1)(x+1)-36=0 | | 8n-6+4n=6 | | n2-8n+20=0 | | 3x-5º+2x=180 | | 7x-8=12-2x | | 15y-10=3(y+1) | | 5.3=x=2.7 | | 0.2=0.43(0.5^x) | | 0=12-20x | | .35x=70 | | -10=-a/8 | | –8−6k=20−13k | | -2=m+6/2 | | 15r=17+16r | | 5.x-50=250 | | -3c-18=18-6c | | 9x-1=39+5× | | 6p-3p=8p-9 | | 19n-14=20n | | 17+6m=7m | | 1/4x=53 | | z−64=3 | | b+83=4 | | 4=3+f | | (2x+5)=22 | | x-4/x+8=-2 | | x-27.7=16.5 | | 5(1+2m)=1/2)8+20m) | | 3+4.5{2d-3}=7.5 |

Equations solver categories