Which table shows a function that is decreasing only over the interval (–1, ∞)?

What is the equation and solution for the sentence? the sum of a number and thirty-one is one hundred thirteen. write the equation as n-31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and add 31 to both sides. the answer is 144. write the equation as n-31=113 and add 31 to both sides. the answer is 144.

The equation respenting the left table is

Find the solution of this system of equation -7x+y=-20 9x-3y=36