a+b-(a*c)-d=(e+f+g)/h a=?

a+b-(a*c)-d=(e+f+g)/h

a - ac + b - d = (e+f+g)/h

將 a - ac 因式分解并成一個a

a(1 - c) + b - d = (e+f+g)/h

移項一左邊只剩a :

a(1 - c) = (d - b) + (e+f+g)/h

右通分母

a(1 - c) = (hd - bh + e+f+g ) / h

兩方除(1 - c)完成

a = (hd - bh + e + f + g) / [h(1 - c)]

約:

a+b-(a*c)-d=(e+f+g)/h*a=?

=>a+b-ac-d=ae/h+af/h+ag/h

We can't find a

I do not have the hints