Help please it ends in 10 mins please hurry

What is the length of the missing leg in this right triangle? 18 mm 24 mm 26 mm 32 mm

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

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