If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
x = 0
x = 0
x = 0
x in (-oo:0) U (0:+oo)
0.8*(15000/x+1) = 4.5 // - 4.5
0.8*(15000/x+1)-4.5 = 0
0.8*(15000*x^-1+1)-4.5 = 0
0.8*(15000*x^-1+1)-4.5 = 0
12000*x^-1-3.7 = 0
12000*x^-1-3.7 = 0
12000*x^-1 = 3.7 // : 12000
x^-1 = 0.00030833
-1 < 0
1/(x^1) = 0.00030833 // * x^1
1 = 0.00030833*x^1 // : 0.00030833
3243.27830571 = x^1
x = 3243.27830571
x = 3243.27830571
| -y+184=258 | | 4x-590=4(884)-590 | | 4x-(x-5)=-2 | | -2g-5+g= | | 8/3(6-3g)=56 | | 252=I(I-4) | | 5(3)=-4+4 | | 5x+7=x^2-5x-2 | | 175m-125m+42750=45255-175m | | 5(2)=-4+4 | | 12/3+4-24/3*8 | | 87-(-36)= | | 1200=45h+1800h | | 252=1(1-4) | | 5(1)=-4+4 | | 3a+2=a-1 | | 186=114-v | | 6n+3=5 | | 11y-16=7y | | 3h/5-18=713/40 | | 2x-3+4x-7= | | 207-x=23 | | 6n+3=10 | | 12m-5=-2(6m+3) | | 4(f+h)-8p=3k | | 259=-v+182 | | 8w^2-14w+5=0 | | 49-121+12+4Y=-3Y+2(3) | | 8y-6y-9=23.24 | | 141=-3x+6(6x-4) | | -5-8f-10=-8f-5 | | -3=4w-7 |