If it's not what You are looking for type in the equation solver your own equation and let us solve it.
x in (-oo:+oo)
x/21 = 28/12 // - 28/12
x/21-(28/12) = 0
x/21-7/3 = 0
1/21*x-7/3 = 0 // + 7/3
1/21*x = 7/3 // : 1/21
x = 7/3/1/21
x = 49
x = 49
| (4x^2+7x)(12x^2-5x-2)=0 | | 2/4=5/x-1 | | 25x+6-27x=3-7 | | 13-1.25x=-2 | | 12b+15=-18+3b | | 15-42=3(x-1)-6 | | 2/3x=-7/6 | | 4ab-7c=2 | | (4/5)(n-10)=(-8/9) | | -6x-5+2x+3=30 | | 3x+34=7x+6 | | F(5)=10x-x^2 | | k*3-2= | | 2c^3-3c^2-4c+6=0 | | 2m+4=4m-6 | | 3lx-7l-2=4 | | 3c-4=11 | | 2(9x-1)=99-7(33-4x) | | 9-2y-9y=86 | | 5xy-3x=6 | | 5/3x=3/6 | | 5z^3+25z^2+30= | | 8x-4y=156 | | 8x-4y=256 | | X/2=12/-3 | | 3x+7y=50 | | 3/x=9/5x(+2) | | 81s^4-1=0 | | 2x+3y=141 | | 5(x)/2-x=x/10-21/5 | | ax+by+cd=e | | 5(x)/2-x=x/6-20/3 |