Solve for the value of N

Yuri, sam and dani had the same math homework last night, but none of them finished it. yuri finished 3/8 of her homework, sam finished 4/6 of her homework and dani finished 1/2. who finished the most math homework? who finished the least amount?

What is [tex] {7}^{98 + \sqrt{4} } - 3 \times (64 \div 2 + 4 - 36) \times a = a + 36[/tex]?

Having a hard time understanding this question (see attachment).