If it's not what You are looking for type in the equation solver your own equation and let us solve it.
u^2-4u^2-12=0
We add all the numbers together, and all the variables
-3u^2-12=0
a = -3; b = 0; c = -12;
Δ = b2-4ac
Δ = 02-4·(-3)·(-12)
Δ = -144
Delta is less than zero, so there is no solution for the equation
| x-0.1x=106890 | | 8t+9t=85 | | 1.6x-(x-2.8)=(.2x+1.5)+.7 | | |4x+5|+4=17 | | -4/3/x=-2 | | -43/x=-2 | | h+17=41 | | 7(x+2)-4(2x-1)=18+x | | 1.2a+10=16.6 | | 2(x-1)+2=3+(x+5) | | P=-x^2+130x-3000 | | -x=0.79 | | 1.29+10=16.y | | 21x-14=15x+10 | | (9x-4)(7x+4)=0 | | 100=4r-60 | | 7+g-9=150 | | 21x-14=15+10 | | 4+2w=-8 | | 3x/12=13/6 | | 5m+17.5=42.5 | | 11k+6k=65 | | 10=-16x^2+80 | | 10=4x-60 | | 91=5w+11 | | 2|m+7|=8 | | -1/7d+4=7 | | -2/5x+1/2=-2/5 | | 7x+35=112 | | a-9/3=7 | | 0.08x=1046 | | x+0.08x=1.08 |