If it's not what You are looking for type in the equation solver your own equation and let us solve it.
3+4-8D+12=0
We add all the numbers together, and all the variables
-8D+19=0
We move all terms containing D to the left, all other terms to the right
-8D=-19
D=-19/-8
D=2+3/8
| 5x^2-8x-4=3x-4 | | 4x+2+3x-7=93 | | -25=y/4-5 | | -11=5p-4-2 | | 24-6x=6(4÷x) | | 2n+16=34 | | -1-k-3=0 | | 3(x-2)-4x=10 | | 21000=34000q+600 | | 3(2x+5)+3=2(2x-7)+10 | | 24-12=3(x-3) | | 5-(2x+4)=(5-2x)+4 | | 7(y-3)-2=-3(-9y+9)-2y | | −3(2x+5)+4x=23 | | (5x/2)−4=(2x−7)/6 | | x-8+2x=5x+20 | | 28-21x=3x+3-11 | | 6y+9=3y―3 | | (2x+30)+(48x)=180 | | 2/7x+1+3=148/35 | | 6a=+4 | | 9v^2-55v=0 | | 5x+7-2x=×-11 | | -2+1/3(6x-18)=14 | | 0=3x+14 | | 90+-6y=-210+12y | | 4(x)-3=45 | | 9r2-18-r2-5=0 | | -5r-4(-1+2r)=-21-8r | | 8r2-23=0 | | 5n-7=4-3(8-6n) | | 3(2k+3)=3+6k |