Which strategy i would use to find 2+8

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts.which pair of fraction cannot be used to find how many pounds of nuts she bought in all.

Solve the equation w^3 = 1,000 i honestly dont know how to punch this into a calculator pls

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial