Answer:
because everything is relative to each other.
Step-by-step explanation: Graphing ordered pairs is only the beginning of the story. Once you know how to place points on a grid, you can use them to make sense of all kinds of mathematical relationships. A linear relationship is a relationship between variables such that when plotted on a coordinate plane, the points lie on a line. Let’s start by looking at a series of points in Quadrant I on the coordinate plane. Look at the five ordered pairs (and their x– and y-coordinates) below.
y=15
5y-20=2y+25 move terms
5y-2y = 25+20 calculate like terms
3y=45 divide both sides by 3
6x-12y=24
x=-6y-4
6(-6y-4)-12y=24
-36y-24-12y=24
-48y=48
y=-1
6x-12(-1)=24
6x+12=24
6x=12
x=2
6(2)-12(-1)=24
12+12=24
24=24 true
and
-(2)-6(-1)=4
-2+ 6=4
4=4 true
let's recall that perpendicular lines have negative reciprocal slopes, so say for a line with a slope of a/b
a perpendicular one will be -b/a.
what does that mean? well, that the lines are perpendicular of course, they meet at a 90° angle, and two straight lines meeting at 90° can only meet once.
since a solution to a system of equations is where the graph meet, and these two meet perpendicularly once, then that means only one solution.
