It would be b. In all, he has $100 to spend since $50+$25+$25=$100. We have x people coming and he has to spend $2.50, $1.50, and $3.00 per person, respectively. The phrase "per person" indicates we must multiply, so we have to multiply each value by "x." To find out how much money he has left, we must subtract. All of this put together is 100-(2.50x+1.50x+3.00x).
Add the like terms and you get 7x. Your final expression would be
100-7x, which is answer choice b.
