If it's not what You are looking for type in the equation solver your own equation and let us solve it.
x in (-oo:+oo)
-12 = x/3 // - x/3
-(x/3)-12 = 0
-1/3*x-12 = 0 // + 12
-1/3*x = 12 // : -1/3
x = 12/(-1/3)
x = -36
x = -36
| 3.5x=-52.5 | | t(t-24)=4 | | T(t-24)=0 | | L=1.23t+144 | | 5+13=-29-9x | | 10x+7=-53 | | z^2+(-2+4i)z+(2-i)=0 | | 15-x+y=14-(-x-y) | | 4x+35=12x-20 | | 4x+7-2x=7+5x-6 | | 4X^2-30x+400=0 | | x-(-x+5)=y | | W=lhp | | H+h^2=98 | | -4(t+5)=0 | | 13x*x= | | 25.00x+0.00=500 | | 9(11-x)-4x=5(21-2x)+9x | | 7+3x-8=17-6x | | X^3+x^2+x+1=60 | | 7+4=711 | | 3x-6x+33=5x+25 | | 8x-12=6x+4 | | -x+2=3x-4 | | -2(7y+4)+8y=(y+5) | | 7x+6x-8x=13+2 | | -2w+4+3w=7-1 | | 6W+2=15 | | 4-x+6=13 | | 3x^2-45x=152 | | -3=-6+3x | | x/2-2=6 |