Write two linear expressions with a sum of -5x+4

Plz help plz give me the answer

Which system of linear inequalities is represented by the graph? x-3y > 6 and y? 2x + 4 x + 3y > 6 and y? 2x - 4 x - 3y > 6 and y? 2 - 4 x + 3y > 6 and y > 2x + 4 no be 2 -1.1 1 2 3 4 5 submit save and exit next mark this and retum be

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?