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)
15*x = (5/8)*x^2 // - (5/8)*x^2
15*x-((5/8)*x^2) = 0
(-5/8)*x^2+15*x = 0
15*x-5/8*x^2 = 0
DELTA = 15^2-(-5/8*0*4)
DELTA = 225
DELTA > 0
x = (225^(1/2)-15)/(-5/8*2) or x = (-225^(1/2)-15)/(-5/8*2)
x = 0 or x = 24
x in { 0, 24 }
| 2y^2+5=-11y | | 4r-7=-2+3r | | 2(2c-3)-1=2c+1 | | 11w=6600 | | bx*4=32 | | -3x=17 | | b*x*4=32 | | (3x+7)*2=32 | | 4mn-12m-48n+144=0 | | 15+g=26 | | 6u-3=-15 | | t+13=21 | | pqr=p+q+r+2015 | | f(x)=4e^5x+3 | | 3q^4-243=0 | | 16x^2+19x+3= | | 7m=25.55 | | t(5)=40 | | 7x=10x+17 | | 8h-14=50 | | F(t)=5t+3e^2t | | 3(2x-3)-2(2-x)-(x+3)=0 | | a-1/6=-2/3 | | 5x+2=12x-4 | | 4x-1/3=3 | | 2x+29/3=x+44/8+2 | | 5y-2z-4y+6z= | | x+x+120%=11000 | | (7+6)9=9 | | x+x+20%=11000 | | (3+6)1=9 | | x+x+1.20x=11000 |