Sandy and Mark have $25.00 each to spend at a book fair, where all students receive a 35% discount. They both want to purchase a copy of the same book, which normally sells for $32.50 plus 10% sales tax. To check if he has enough to purchase the book, Mark takes 35% of $32.50 and subtracts that amount from the original price. He takes 10% of the discounted selling price and adds it back to find the purchase amount.

Sandy takes 65% of the original purchase price and then computes 110% of the reduced price.

Is Mark correct?

Is Sandy correct?

Do they have enough money to purchase the book? Explain your answer using complete sentences and show your work.

$30.32

step-by-step explanation:

65.00*.12=2.80

65.00-2.80=57.20

57.20*1.06=60.632

60.632/2=30.316

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

нιѕ яαтє ιѕ 1/4 σя .25 ριєѕ ρєя мιиυтє

нσρє ι ¢συℓ∂ нєℓρ уσυ.