If it's not what You are looking for type in the equation solver your own equation and let us solve it.
21a=6a
We move all terms to the left:
21a-(6a)=0
We add all the numbers together, and all the variables
15a=0
a=0/15
a=0
| 8x-8=5+8x | | x+9=5(10x-8) | | 3a=13a | | 5x+6(x-3)=59 | | 71/2+x=-2/5 | | |8k|=72 | | 3(a)=13a | | 11/13=7/u | | 11/13=7u | | x-6(26)=20 | | 2(9x+3)-4=18x+2 | | 3(a-7)=6a | | 10-(3z-4)=8-4z | | 16x+6=15x-4 | | -82x-9=20-12x | | 3(a–7)=6a | | 3d-6=5d=40 | | 6(x-9=4(x-5) | | 2a-19.9=a+2.1=a-2.5=19.5 | | 3.25+a=8.6 | | -9+x=52 | | -5(z+6)=-6z | | 9m+32=37 | | 9.03+y=1.5 | | 6(x-9=4(x-5 | | 11x-5+17=11x+12 | | -7x-3=-8 | | (x+8)(2x+5)=0 | | 8x+4-2x=1+5x+9 | | 7x/2=56 | | 92.99+.89=x | | N/3+20=n |