If it's not what You are looking for type in the equation solver your own equation and let us solve it.
a8.4=21.3
We move all terms to the left:
a8.4-(21.3)=0
We add all the numbers together, and all the variables
a8.4-21.3=0
We move all terms containing a to the left, all other terms to the right
a8.4=21.3
a=21.3/1
a=21.3
| 8x+9x^2=52 | | h19.1=13.5 | | x.4 | | 8−5a=13 | | 15/25=12/f | | 500-x=321 | | 3.9i=29.62 | | 3n=634 | | X/5+7/6=6/5+x/6 | | 11k-4K-10=-10+7k | | 0=2/x | | X^2/45+y^2/5=1 | | X(0)+3y=1000 | | 18b+1=17b+11 | | 3n-11=28+6n | | 26t+14=4 | | 5-m=3⅛ | | 234=w-520 | | z+226=454 | | v/22=12 | | 503=k+39 | | A=4xB=20 | | n-79=763 | | x+13(4x)=9 | | c-297=651 | | (2x-5)=110 | | g-377=409 | | (2x-5)=10 | | 6a-6=3a+9 | | f/31=9 | | (5x-10)(3x+20)=180 | | 5(x+5)=5x-25 |