If it's not what You are looking for type in the equation solver your own equation and let us solve it.
21+x=84
We move all terms to the left:
21+x-(84)=0
We add all the numbers together, and all the variables
x-63=0
We move all terms containing x to the left, all other terms to the right
x=63
| X2-64x-768=0 | | 15=5b+11 | | 12x+40=2x+90 | | 5x-7-4x=3 | | x/5-33/5=-2/5 | | 24-4x-x=84 | | 1(x-7)=41 | | 0.4(x-3)=4 | | 6.5g+4=2.5g+12 | | 5x+3x−2=3−5+8x | | 12x+5=4x+5+8x | | 4h−13=3 | | C=(77-32)x(5/9) | | –4+2d=–8+2d | | -7x+6+2x=-9 | | 6x−5=3x−16 | | 6(2x+4)-3x=7(x-1) | | -3(s-63)=-4 | | 1x+2/7x=180 | | 6x-10=50x-4 | | 6-(-1/3)=8x | | 1x+5=-33+9x | | –3(s−63)=–48 | | 5x+(6x–260)= | | (4x-12)=(10x-72) | | 3z-15=3 | | 8+5f=–4f+1+8f | | (4x-12)+(10x-72)=180 | | 3m+6=12-3 | | -24=6(e-39) | | –4+16c=18c–4 | | -2a+9=15-8a+3a |