What does it mean for a ordered pair to be a solution to a linear equation

What is the solution of sqrt x+2-15=-3

An equation representing lyle’s hedge-trimming business is a = 12n - 300 where a is the amount of profit or loss in dollars and n is the number of hedges trimmed. how would the graph of lyle’s business change if the equation a = 10n - 300 represented his business? the graph would be flatter. the graph would be steeper. the graph would start closer to the origin. the graph would start lower on the y-axis.

The diagram shows corresponding lengths in two similar figures. find the area of the smaller figure. a. 14.4 yd2 b. 24 yd2 c. 26.4 yd2 d. 28