If it's not what You are looking for type in the equation solver your own equation and let us solve it.
a in (-oo:+oo)
1/5-(9/10) = a/3 // - a/3
1/5-(a/3)-(9/10) = 0
1/5-(a/3)-9/10 = 0
-1/3*a-7/10 = 0 // + 7/10
-1/3*a = 7/10 // : -1/3
a = 7/10/(-1/3)
a = -21/10
a = -21/10
| (7-6x)+5= | | -5a-2(-7a-10)=128 | | 3y+5y-8=10 | | -6x+20=x+34 | | ln(a+3)+ln(a-3)=16 | | -2n+2(3n+14)=-20 | | (n^3-2n^2)-(n-2)=0 | | 25.6=u/8 | | 4a^2=24 | | 100+b=500 | | 30x+9000=9690 | | 5x=31.25 | | 4d+2(4d+7)=-106 | | 4x+29=4x+29 | | 50=6x+3x+5 | | 30*300+9000=x | | 30*200+9000=x | | 6+2z+3z-17=180 | | 10-3+7+x+4=2 | | 3x+5=103sqrt(3x+5) | | 4x^2-3x+0=0 | | (8x+4)+(5x+19)=4x+29 | | B^2+8+6b=0 | | 64x^2+16x=4 | | 30*100+9000=x | | -8tan^2(x)+10tan(x)-3=0 | | x+.4=17 | | (x-8-2i)(x-8+2i)=0 | | -43=-5c+4(2c+7) | | x^2+11=38 | | -100y-6-2=-8y-9 | | 9x+5y-10=0 |