If it's not what You are looking for type in the equation solver your own equation and let us solve it.
-8-7+x=21
We move all terms to the left:
-8-7+x-(21)=0
We add all the numbers together, and all the variables
x-36=0
We move all terms containing x to the left, all other terms to the right
x=36
| -12x-29=-8x-17 | | 2n+4/5=10 | | X+x=2000000 | | 89=4x-17 | | 18x-121=11-72 | | 8+7-8+x=-21 | | 43=3x+1x*3 | | 2800+3000x=30000+2800x | | 15x-85=8x-43 | | 1x+-4=2x | | 43=3x+x+3 | | 12y+10y+12=80 | | 5+21+x=-33 | | -12=u/3-3 | | -x+66=-15x+2-2x | | -9x+60=-5x+32 | | 2-5x-4x=101 | | 55x+75.25=680.25 | | 6x+9=3x=12 | | 2x+21=x+12 | | y+6=2y2+72 | | 6x+2-5x=7 | | y+6=2y2+72 | | -275=11(1+13n) | | 7c+12=-4c=78 | | -23-5+x=43 | | -x+66=-15+2-2x | | 01x=0.3(x+2) | | -2+7x-x=52 | | 2+4x=5+2x+1 | | 9y=25-5y | | 6x+37=3x+19 |