A hair salon charges a fixed rate of $25.00 for a haircut and then an additional $15 for any other services. Write a function to model the cost of services there and then evaluate it if you also get a shampoo, highlight, and blow dry.

Simple,

you have a fixed rate of $25, meaning you get a haircut, it's $25

ANY other service is an extra $15

So, let's make the equation ...

y=15x+25

Now, to just get a haircut it's $25.

But, let's say you get a haircut+shampoo

It'd be ...

y=15 (1) + 25

y=$40

Another one ...

You get a haircut+shampoo+highlight

y=15 (3) + 25

y=$70

And so on, and so forth.