How to solve 5x = 8x (X-15)

How to solve 5x = 8x (X-15)

8x²-120x-5x=0
8x²-125x=0
x(8x-125)=0
x=0,x=125/8

x^2+8x+13/x^2+8x+15-x^2+5x+4/x^2+5x+6
2/x^2+4x+3+2/x^2+8x+15+2/x^2+12x+35

The original formula = (X & # 178; + 8x + 13) / (x + 3) (x + 5) - (X & # 178; + 5x + 4) / (x + 2) (x + 3) = (X & # 179; + 10x & # 178; + 29x + 26-x & # 179; - 10x & # 178; -- 29x-20) / (x + 2) (x + 3) (x + 5) = 6 * (X & # 179; + 10x & # 178; + 31x + 30)

How to do x ^ 2-6x + 8 and x ^ 2-3x-28 with matching method

x²-6x+8
=(x²-6x+9)-1
=(x-3)²-1
x²-3x-28
=(x²-3x+9/4)-121/4
=(x-5/2)²-121/4