Question

y=1-x²/1+x²怎么变形为x²=1-y/1+y

Answer 1

y = (1 - x²)/(1 + x²)

两边同乘以(1 + x²):(1 + x²)y = 1 - x²

y + x²y = 1 - x²

移项:x²y + x² = 1 - y

x²(1 + y) = 1 - y

x² = (1 - y)/(1+ y)

请注意用括号把问题表示清楚,否则很容易有误解.