Carmen has taken out a loan for $800 to buy
a car. she plans to pay back the loan at a
rate of $40 per month.
how long will it take carmen to pay back her loan?

20

Step-by-step explanation: 800=40x, x= 800/40, x=20

20 months or 1 year and 8 months

Step-by-step explanation:

Take 800 and divide it by 40 which equals 20. 20 would be the amount of months that it would take Carmen to pay back her loan. But if you wanted to simplify it into years and months then it would be 1 year and 8 months.

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