If it's not what You are looking for type in the equation solver your own equation and let us solve it.
4x^2-10x+21=0
a = 4; b = -10; c = +21;
Δ = b2-4ac
Δ = -102-4·4·21
Δ = -236
Delta is less than zero, so there is no solution for the equation
| -3(9-4n)-4=8n-9(n+12) | | 6x+12=6x-40.8 | | -k+10=-2k | | 2(x)^(3/4)+4=8 | | 5(x+4)-3x=x+10+x | | (2x-2)+(×+1)+×(x+1)=(2x-9)+(×+1)(×8)+x | | -12n-16=20-8n | | 3-4y=16 | | 5.35+10.2m=0.46+10.3m+6.57 | | 4x+30=52+34 | | n1/6=5 | | 4x+30=52 | | 8+2v=v+2 | | -15j+19=-16j | | 9+9×m=9 | | 8x-18=4x+30 | | 42^2-22x-42=0 | | -4(-2x-8)=48 | | 17-x=1/3.15=6 | | 13.04-10.8u=-17.78-15.4u | | 2(-1x-3)=3+x | | N-36=5m | | 6y-19+20y=5+14y | | -4x+28=4(-3x-7) | | 5x-2+8x=4x-2 | | -11-2g=-8g+17-4 | | 8x=28+2x | | 8z-10=6+10z | | 2m-16=4m+20 | | 19.24+0.5w=-0.8w | | 400-9y=40 | | 450x+13000=13450 |