Step-by-step explanation:
There are two commonly recognized beginner methods to solve a system of equations. The first is elimination and the second is substitution. I will go over both of them here.
Substitution:
[tex]y=-2x-9, y=-5x-21[/tex]
[tex]-2x-9 = -5x -21[/tex]
[tex]3x=-12[/tex]
[tex]x=-4[/tex]
[tex]y=-5(-4)-21[/tex]
[tex]y=-1[/tex]
Elimination:
This method is a bit hard to explain without visual aid, but I'll try my best :)
In elimination you can subtract each value with a common variable from its counterpart in the other equation. For this example, subtract y-y to get 0, -2x - (-5x) to get 3x, and -9 - (-21) to get 12.
Thus,
[tex]-12=3x[/tex]
[tex]x=-4[/tex]
[tex]y=-5(-4)-21[/tex]
[tex]y=-1[/tex]
Hope it helps and lmk if you need more help <3 :D
