What is the reason for line 2? question optionsaddition propertymultiplication propertydivision property

Find the value of the variable and the length of each secant segment.

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Sketch the region enclosed by the given curves. decide whether to integrate with respect to x or y. draw a typical approximating rectangle and label its height and width. y= 5x, y=7x^2then find the area s of the region.