Arthur paid $0.84 for 0.25 pounds of potato salad. how much does one pound cost?

3.36

Step-by-step explanation:

.84 * 4

3.36

$3.36

Step-by-step explanation:

So,

0.25 of one pound is the same as 25 percent of 1 pound. 25 percent goes into 100 percent 4 times. Therefore, if we multiply 4 by the price per 25 percent, we should get the answer.

1 lb divided by .25 is 4

4 x .84 (Unit cost for every .25)

3.36

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