If it's not what You are looking for type in the equation solver your own equation and let us solve it.
x^2+15=-66
We move all terms to the left:
x^2+15-(-66)=0
We add all the numbers together, and all the variables
x^2+81=0
a = 1; b = 0; c = +81;
Δ = b2-4ac
Δ = 02-4·1·81
Δ = -324
Delta is less than zero, so there is no solution for the equation
| 2m-4.1=1.9 | | 5x*2/x=10 | | 1/6x=1/2-1/3 | | (6+x)+3x=30 | | 1.875=x*0.5+1 | | 90+53=u | | 11.5^2+x^2=20^2 | | X3-36x-4=0 | | x4+12=16 | | 11+-5w=-9 | | n2+10=14 | | y+3=-9-18 | | 11x+41=4x-36 | | 10x-51=2x+45 | | Y=-4+0.2x | | 4y-21=y+15 | | 5=7x-13 | | 7v+21=-5(v+3) | | 7a-10=10 | | -5y-13=-7(y+1) | | 0.125=1/2^x | | 2y+2(y+4)=-12 | | d+25=67 | | -234=-6(4+7a)+7a | | -3/2x=2/5 | | -9=5(x-3 | | 5(3+7n)-7n=-209 | | -13x=31 | | X=0.3x120= | | 0.2x-0.2=0.25x+2 | | 7(x-8)=-98 | | -3x(3x-2)(7x+8)=0 |