If it's not what You are looking for type in the equation solver your own equation and let us solve it.
z in (-oo:+oo)
(-3/10)*z = -12 // + 12
(-3/10)*z+12 = 0
12-3/10*z = 0 // - 12
-3/10*z = -12 // : -3/10
z = -12/(-3/10)
z = 40
z = 40
| 5-x/3=-15 | | 2x+8t=32 | | 3a+-5=6c-5 | | 6.4k=-64 | | (7/6)=(42/z) | | 9q-7=7q+7 | | -5/6s=-15 | | x/x-2+x/x^2-4=x+3/x+2 | | 2x-50= | | 9t-9=3t+15 | | 36=r^2-12r+36+r^2-12r+36 | | z=27x+13y | | x/x-2+x/x*2-4=x+3/x+2 | | -6r+30-4r=-30 | | 10x^2*3x=4 | | x+(x+3)+2(x+1)=5(x+2) | | x-x^2=10-1 | | 7x^2-x/2=168 | | 5(9x-5)+8=7(5x+3) | | 7.50=(3x+0.05)+x+(x+0.10) | | 8n-9=-9n+11 | | 8/3(x+1)=8 | | b-4=-9+b | | 30=20+2x | | m-21=47 | | 75+15(4d-1)=240 | | 2x+3(x+1)=4(x-1) | | 8+2x-1=9x+14-6x | | 1.6h-72=1h-30 | | p-16.7=11.8 | | (-62+3x-28)/x-6 | | 100=2x+x-10 |