Can anyone help me w this pweese??

Is a positive integer raised to a negative power always positive

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

Factor the following expression. 27y3 – 343 a. (3y + 7)(9y2 + 2ly + 49) b. (3y – 7)(9y2 + 2ly + 49) c. (3y – 7)(932 – 217 + 49) d. (3y + 7)(92 – 2ly + 49)