Workbook activity chapter 1,lesson 3

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

Haruka hiked several kilometers in the morning. she hiked only 66 kilometers in the afternoon, which was 25% less than she had hiked in the morning. how many kilometers did haruka hike in all?