If it's not what You are looking for type in the equation solver your own equation and let us solve it.
3x+1x=21
We move all terms to the left:
3x+1x-(21)=0
We add all the numbers together, and all the variables
4x-21=0
We move all terms containing x to the left, all other terms to the right
4x=21
x=21/4
x=5+1/4
| 4x-5+8x=15+7 | | (4x-3)(4)=(3)(2x+8) | | 8x+1.6=6×+2.8 | | -8/3k=3/8 | | 1/4y+9=1/7y | | 2c=1/5 | | ((k+5)(k+2))/2=44 | | 4(-4x-4)=36 | | 12-t2=0 | | 6x–6=-12 | | √(5x+6)+3=√(3x+3)+4 | | 107/6=7m/2-3m-1/3 | | 23v+8=70 | | 6y-7=7y+5 | | X2=6x-5 | | Y+1=-4/5(x+5) | | (x+6)=400 | | 31/5=x-11/2 | | 21/2=y+11/4 | | 3(2x− 7)=5x+17+x | | 25x2-20x+4=0 | | x+x-135+1/10x=180 | | x+3000000=300000 | | 2c(c-8)=30 | | X2º=6x5 | | a2+16=25 | | 2x+4x-7=34 | | x+209=209 | | 11a^2-6=0 | | 5x+4x+3x=12x | | 9x-27=6x-66 | | 8x+26=8.33333 |