Question in photo; pretty sure it’s an easy question i just don’t understand it

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?

Solve 13 + w/7= -18 (w/7 is a fraction)

Paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.