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 (1,8)
y = 4 × 2 x

Question 2:

A is (0,4) and
B is (1,12)
y = 4 × 3 x

Question 3:

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

Question 4:

A is (1,-15) and
B is (2,-45)
y = -5 × 3 x

Question 5:

A is (2,8) and
B is (4,32)
y = 2 × 2 x

Question 6:

A is (3,-24) and
B is (4,-48)
y = -3 × 2 x