中五數學 , 離差的量度

10y^2= 2y
5y^2 - y = 0
y(5y - 1) = 0
y = 0 or 5y - 1 = 0
y = 0 or y = 1/5

2007-06-05 19:47:39 補充：
ooops...10y^1/2 = 2yy^1/2 = y/5y = y^2 / 25y^2 - 25y = 0y(y - 25) = 0y = 0 or y = 25

y*y *10=2y
y *y =y/5
5y*y =y
√y =5
y =5*5
y=25


y*y=y平方
5*5=5平方