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,-15)
y = -3 × 5 x

Question 2:

A is (0,-4) and
B is (1,-16)
y = -4 × 4 x

Question 3:

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

Question 4:

A is (4,243) and
B is (5,729)
y = 3 × 3 x

Question 5:

A is (4,-324) and
B is (5,-972)
y = -4 × 3 x

Question 6:

A is (1,9) and
B is (5,729)
y = 3 × 3 x