If it's not what You are looking for type in the equation solver your own equation and let us solve it.
0.40x+0.20(100-x)=21
We move all terms to the left:
0.40x+0.20(100-x)-(21)=0
We add all the numbers together, and all the variables
0.40x+0.20(-1x+100)-21=0
We multiply parentheses
0.40x-0.2x+20-21=0
We add all the numbers together, and all the variables
0.2x-1=0
We move all terms containing x to the left, all other terms to the right
0.2x=1
x=1/0.2
x=5
| x2^=18 | | x1^=16 | | x=0.8-7 | | 8(5+4x)+11-12=-5(3-7x)-13 | | X²+3x-13=0 | | x^2=288/6 | | -14b=-350 | | D/6+1,140+d/4=1,380 | | x^2=882/10 | | -8x-19=-6 | | 6x-4+3x+2=4x+3+x | | 6x=211224x | | 18x-9=-12 | | x+4=7-19 | | b+5=-21 | | 4k^2+2k=-1 | | (2x-1)(x-2)(x+3)=0 | | 5^4x-5=1/25 | | 80(t+3)=120t | | 3x2−11=16 | | (30-x)/5+4=8 | | 2n²+7n+9=0 | | 4x+7+6x+3+90=180 | | −9d=45 | | 2x+3=x+10+7 | | (5x+3)(6x+4)=0 | | 9.6(x-1.75)=-19.2 | | 4.75x=54+2.5 | | x+1=2x+8+7 | | 3.3+10m=6.67 | | 14(2x+7)+3=14(2x) | | (7-2x)(7+2x)=6 |