有關中學數學

你的意思是不是主項轉換為 x？希望我的理解沒錯。

rx / s - (x+2) = 3

rx / s = 3 + (x+2)

rx / s = x + 5

rx = s(x + 5)

rx = sx + 5s

rx - sx = 5s

(r-s)x = 5s

x = 5s / (r-s)

rx／ｓ－(x+2)=3
rx／ｓ=x+5
rx=sx+5s
rx-sx=5s
x(r-s)=5s
x=5/r-s

答案

rx/s -x-2=3
rx/s - sx/s = 5
rx/sx = 5s
x = 5s/(r-s)

rx/s - (x+2) = 3
x(r/s) - x - 2 = 3
x(r/s - 1) - 2 = 3
x[(r-s)/s] = 3 + 2
x[(r-s)/s] = 5
x = 5s/(r-s)