X is partly constant and partly varies with y when y is 3 and x is 7 and y is 6 ,x is 9

Question

1.find the relationship
2.find x when y is 4

Answer 1

x = a + by
so
a + 3b = 7
a + 6b = 9
Now find a and b, then do #2.

Answer 2

X is parthy constant and parthy varies with y=3 x=7 and when y=6,x=9
Find the relationship between x and y
Find x when y =4

Answer 3

X is parthy constant and parthy varies with y=3 x=7 and when y=6,x=
9
Find the relationship between x and y
Find x when y =4