Question

A coordinate plane going from negative 5 to 5 in increments of 1 labeled every 5 units on the x-axis and from negative 1 to 15 in increments of 1 labeled every 5 units on the y-axis.▼Click for Long DescThere are 2 points marked and labeled at left parenthesis negative 1 comma 0.7 right parenthesis and at left parenthesis 2 comma 5.6 right parenthesis. A curve is drawn through the 2 points.(1 point)Responsesy=1.4⋅−(2)xy is equal to 1 point 4 times negative 2 to the x th powery=−1.4⋅(2)xy is equal to negative 1 point 4 times 2 to the x th powery=2⋅(1.4)xy is equal to 2 times 1 point 4 to the x th powery=1.4⋅(2)x

Answer 1

y = 1.4·2^x

Reason: let y = a·b^x. From (-1,0.7): a/b = 0.7. From (2,5.6): a·b^2 = 5.6. Substitute a = 0.7b into the second: 0.7 b^3 = 5.6 → b^3 = 8 → b = 2. Then a = 0.7·2 = 1.4.