f4 maths.

有咩唔明,煩請來信
以下將解答

2014-01-23 20:41:06 補充：
(1) Pass through (3,1) and (4,3)
(y-1)/(x-3)=(3-1)/(4-3)
y-1=2x-6
2x-y-5=0

2014-01-23 20:43:01 補充：
(2) Pass through (2,7) and (5,1)
(y-1)/(x-5)=(7-1)/(2-5)
(y-1)/(x-5)=-2
y-1=10-2x
2x+y-11=0

2014-01-23 20:44:53 補充：
(3) Pass through (0,3) and (4,1)
(y-3)/(x-0)=(1-3)/(4-0)
(y-3)/x=-1/2
2y-6=-x
x+2y-6=0

2014-01-23 20:46:49 補充：
(4) Pass through (-4,-6) and (3,1)
(y-(-6))/(x-(-4))=(1-(-6))/(3-(-4))
(y+6)/(x+4)=(1+6)/(3+4)
y+6=x+4
x-y-2=0