If it's not what You are looking for type in the equation solver your own equation and let us solve it.
42=21x
We move all terms to the left:
42-(21x)=0
We move all terms containing x to the left, all other terms to the right
-21x=-42
x=-42/-21
x=+2
| 5k+7=3(k+6)+2k | | x-12x=2x-10 | | 4x²+16x+8=0 | | −35x−78=−34 | | 2=5v-3 | | 8^-2/3=p | | -11-(-29)=x/10 | | 8^2/3=p | | 5a+3=4 | | 3x^2-13x^2-10x=0 | | 3x-5/2=6 | | 14=5(v+7)-8v | | -5(x-3)-3x=4-8(x+4) | | X-7=x*3+3 | | 8/3x=96 | | 3000r^2+2000r^2=408 | | n2+10n+27=0 | | W^(2)=13w-40 | | 4x+70=9x-5= | | 5+2x/3=4x+7 | | 3x=1=-2 | | 11x-25=4x+10 | | (3x-7)-(4x-2)=0 | | 4x=1=45 | | 6xx5=x | | 10^x=350 | | 0=-16t^2+48t–32 | | 0=-16t2+48t–32 | | 2x+1/3x=96 | | -1/2(-3/2x+6x+1)-2x=121/4 | | 4.9t^2+20t=300 | | 0=-t2+4t+5 |