Question

Elsa wants to save $500 to buy a TV. She saved 18 each week. The amount A (in dollars) that she still needs after w weeks is given by the following function.A(w)=500-18wIf Elsa still needs $194 how many weeks is she been saving?How much money does else’s still need after seven weeks?

Answer 1

a) We set the given equation to 194, and solve for w:

`\begin{gathered} 194=500-18w,\text{ } \\ 18w=500-194, \\ w=(306)/(18), \\ w=17. \end{gathered}`

b) If we evaluate the given function at w=7 we get:

`A(7)=500-18\cdot7=374.`

Answer:

Elsa has been saving for 17 weeks.

After 7 weeks she still has to save $374.