I need help this is very hard:

8 1/3xy+4/5=9/10

Mustafa contributes 11% of his $67,200 annual salary to his 401k plan. what is his pretax income

Mr. brettler is hanging up a 5-foot tall rectangular welcome sign in the gym. he has drawn a sketch on a coordinate grid. he has the lower vertices of the sign at (9, –3) and (–6, –3). where would the upper vertices be on the grid?

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)