Question

Suppose you have a $180 gift card for gas. You spend on average $15 per week for gas.

a) Write a function to model this situation where w is the number of weeks and g(w) is the value in dollars
remaining on the card.

Answer 1

a) g(w)=180-15w; b) g(6)=90$.

Explanation:

a) if w - the number of weeks, then the money spent in those weeks, is 15*w. If the initial sum is 180$, then the remaining part on the card is 180-15w; finally, g(w)=180-15w;

b) if to substitute w=6 into the equation, then g(6)=180-15*6; ⇔ g(6)=90.