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

Question 1:

A is (0,4) and
B is (1,20)
y = 4 × 5 x

Question 2:

A is (0,4) and
B is (2,36)
y = 4 × 3 x

Question 3:

A is (0,3) and
B is (1,15)
y = 3 × 5 x

Question 4:

A is (2,-27) and
B is (5,-729)
y = -3 × 3 x

Question 5:

A is (1,4) and
B is (3,16)
y = 2 × 2 x

Question 6:

A is (1,-10) and
B is (5,-160)
y = -5 × 2 x