If it's not what You are looking for type in the equation solver your own equation and let us solve it.
(z-9)(z+7)=0
We multiply parentheses ..
(+z^2+7z-9z-63)=0
We get rid of parentheses
z^2+7z-9z-63=0
We add all the numbers together, and all the variables
z^2-2z-63=0
a = 1; b = -2; c = -63;
Δ = b2-4ac
Δ = -22-4·1·(-63)
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$$\sqrt{\Delta}=\sqrt{256}=16$$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-16}{2*1}=\frac{-14}{2} =-7 $$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+16}{2*1}=\frac{18}{2} =9 $
| v-8.86=3.32 | | -0.04×0.36e-0.36+6.4=0 | | (15x+29)=(26x-23) | | w+1.6=8.24 | | -x/3-5/6=-4/3 | | -x/3-5/6=-473 | | w+1.46=8.22 | | 41+16h=825 | | 5(t+20)=-40 | | -4(v-2)=-2v+2 | | -0.04×0.36e(-0.36+6.4)=0 | | -7x+39=3(x-7) | | -5(y-3)(-y-9)=0 | | X=7.5+5y | | -6(y+1)=-4y+14 | | -9=j+997/10 | | w/13+120=126 | | 6(q-813)=702 | | -16(h-989)=288 | | 3(x+6)^2=48 | | p/27+-825=-798 | | 8y=21=y | | 1.9(10.3r-2.6)=88 | | 1.5x+12=2.5x-12 | | -10(q-100)=40 | | y/10+19=24 | | -4u+2(u+8)=22 | | -10(v+8)=30 | | -52=y/2 | | 21=-6y+3(y-2) | | 90=5(r-71) | | -y/7=-60 |