2 ÷ 1 _ _
5 7

i am too dumb to do this myself so help

Determine the relationship of ab and cd given the following points

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

Write 5(6x+4)-2(5x-2) in the form a(bx+c) where a,b and c integers and a> 1