If it's not what You are looking for type in the equation solver your own equation and let us solve it.
2x^2-4x-641=0
a = 2; b = -4; c = -641;
Δ = b2-4ac
Δ = -42-4·2·(-641)
Δ = 5144
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}$$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$
The end solution:
$\sqrt{\Delta}=\sqrt{5144}=\sqrt{4*1286}=\sqrt{4}*\sqrt{1286}=2\sqrt{1286}$$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-2\sqrt{1286}}{2*2}=\frac{4-2\sqrt{1286}}{4} $$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+2\sqrt{1286}}{2*2}=\frac{4+2\sqrt{1286}}{4} $
| 15x-8=46 | | (3x+1)^3=64 | | 12x=16(9) | | -87=14x+2 | | y+6.16=8.64 | | 20(x+4)=8(4x+1) | | 6x-7=-86 | | k-3-1=-6 | | 400t+0.77=0.91 | | 300+25m=180+40 | | 5=f/25 | | 2/x=15/6 | | -71=-5x+6 | | x(5)=59 | | *x*(5)=59 | | 9p-1=-28 | | 7+35x=-133 | | k/9=91/12 | | -6-2m=1- | | T=3s+3.52 | | 14p-16=-114 | | 8x+7=2(3x+6) | | 2y-9+8=-16 | | 6(5x+1)=6 | | -8m-72=-40 | | 150m-100m+38,200=40,200-150m | | -8/5x=54 | | 28=y+10 | | 480=20(x+5) | | 7(3+2x)=77 | | 3x2–33x=-30 | | -8+6a+6a=-20 |