On a coordinate plane, the x-axis is labeled Minutes and the y-axis is labeled Gallons (in hundreds). Point A is (3, 12), point B is (6, 7), point C is (12, 3). The graph shows two points from the table representing a proportional relationship.
A 2-column table with 3 rows. Column 1 is labeled Minutes (x) with entries 1, 2, 3. Column 2 is labeled Gallons (y) with entries 400, 800, 1200.
Which point corresponds to the last entry in the table?

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places