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,-50)
y = -2 × 5 x

Question 2:

A is (0,-4) and
B is (2,-16)
y = -4 × 2 x

Question 3:

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

Question 4:

A is (3,-135) and
B is (5,-1215)
y = -5 × 3 x

Question 5:

A is (2,27) and
B is (3,81)
y = 3 × 3 x

Question 6:

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