You invested $500 in a savings account and after three years you had $650 in your bank. what was the interest rate? use the equation i=prt. where i stands for interest on the original investment, p stands for the amount of the original investment, r is the interest rate, and t is the time. write your answer in a percent form.

An increase of 43.3% per year

Step-by-step explanation:

using the equation, plug in the respective variables. 650 =500R3, 3 times 500 is 1500. 650=1,500R. divide both sides by 1500 to get .4333, 3 repeating. .433 in percent form is 43.3%. (I just use 650 out of 500 or 650/500 which is 1.3 divided by 3 because 3 years to get the same amount)

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