How to solve it and explain

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.

Write the fraction 9/50 as a decimal if needed round to the nearest hundredth

3questions show how you solved the problem 1. subtract & simplify (–y2 – 4y – 8) – (–4y2 – 6y + 3) 2.multiply and simplify 2x2y3z2 · 4xy4x2 3.multiply and simplify (x – 4) (x2 – 5x – 6)