Question

已知y与z成正比例，z+1与x成正比例，且当x=1时y=1，当x=0时y=-3，则y与x的函数关系式是

Answer 1

设 z=ky, z+1=tx,
ky+1 = tx
k+1 =t
-3k +1 =0
k = 1/3
t= 4/3
1/3 y +1 = 4/3 x
y = 4x - 3

Answer 2

y=mz z+1=nx
y=mnx-m 当x=1时y=1，当x=0时y=-3
mn-m=1
-m=-3
m=3
n=4/3
y=43