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-((7/3)*x)-21 = 0
X+(-7/3)*x-21 = 0
X-7/3*x-21 = 0 // - X-21
-7/3*x = -(X-21) // : -7/3
x = (-(X-21))/(-7/3)
x = -3/7*(21-X)
x = -3/7*(21-X)
| 2=w+8 | | r^3-8r^2+19r-12=0 | | 7x+46=3x+18 | | 3/8y-1/4x3/4 | | u/3=51 | | -3x-12=5x-15 | | 5x^4-36x^3+54x^2-92x+32=0 | | 6x+2+7x=67 | | a+3a=504 | | 294.3-x/30=x-98.1/20 | | 6*0-y=9 | | 4x-20=3y-15 | | -12+3x=212 | | -12+3x=2 | | .25+.4x+1=2.25 | | 18y-9=2y+14 | | 4x+5=1x+10.5 | | .5x-.6*0=-6 | | 10-x-7x=-14 | | 5-x/7=x-5/8 | | 39X1/3 | | 3(5-2y)=27 | | 39*1/3 | | 13p^2+81p-196=0 | | 51=5x+6x-4 | | -5m+3(m-5)=-(2+15) | | 4x^2+10=2x+21 | | 1.2x-.125x^2+32=0 | | -9(6m-3)=6(1+4m) | | -2c+1=-5 | | -5x+8+7x=30 | | 13v-11v+v=18 |