Exponential Functions: Find the equation through the points A and B in the form y = a b x

Question 1:

A is (0,-2) and
B is (2,-18)
y = -2 × 3 x

Question 2:

A is (0,4) and
B is (2,64)
y = 4 × 4 x

Question 3:

A is (0,-4) and
B is (1,-8)
y = -4 × 2 x

Question 4:

A is (2,-20) and
B is (3,-40)
y = -5 × 2 x

Question 5:

A is (2,-16) and
B is (3,-32)
y = -4 × 2 x

Question 6:

A is (4,-162) and
B is (5,-486)
y = -2 × 3 x