Complete the following questions.
Winona and Takoda are shopping for a present for their mother. The chart shows several possible presents. There is no sales tax in the state where they live.
a. Write two expressions in terms of d to show how much Winona and Takoda would pay in total if they buy their mother the set of power tools.

b. Let the value of d equal $79.00. Calculate the total cost of each of the possible presents for the value you chose. Then write a sentence telling Winona and Takoda which preset to buy for their mother if they want to spend the least amount of money.