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

Question 1:

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

Question 2:

A is (0,2) and
B is (1,4)
y = 2 × 2 x

Question 3:

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

Question 4:

A is (3,-135) and
B is (4,-405)
y = -5 × 3 x

Question 5:

A is (1,10) and
B is (4,80)
y = 5 × 2 x

Question 6:

A is (1,-12) and
B is (3,-108)
y = -4 × 3 x