If it's not what You are looking for type in the equation solver your own equation and let us solve it.
-1a+21=21
We move all terms to the left:
-1a+21-(21)=0
We add all the numbers together, and all the variables
-a=0
a=0/-1
a=0
| 2x²-84x=0 | | –11y−1=–9y+17 | | -8y-16-16=16 | | 5x+10-21=2x+14 | | 6x–10=17–3x | | 2y+1=4y–7 | | x−20=15 | | 4x+9-2x=3+2x+6 | | 50+10+4=8y | | 4+c=19.50 | | 2(n+1)+1=(n–5)+(n–2) | | 4y=6+6 | | 12x+5=100 | | 28=y+25 | | 0/7n=84 | | 1323=x | | 5x-6(3x-20)=42 | | 8=-5+p/6 | | 3=x/3.5 | | n=9,3n-(36÷6) | | 63=x-19 | | 10=-5+h/2 | | 2(9x+6)=48 | | 13(y−9)=−4y+13/3y−3 | | 2*x=52 | | (4/x+2)+6=14/2x+ | | 5n²–30n+40=0 | | 59+r=118 | | -4(w+5)=20 | | 5+r=118 | | 2x^2-6x-20=16 | | 2x-1.5=11.5 |