This week in math I learned how to solve a system using substitution.

You start with two equations like x+2y=4 and 3x+2y=0. Then you would need to find the equation that looks the easiest to use as a substitution (usually the one with a variable that has a coefficient of one). Then you would rearrange the equation so that only the variable is one one side of the equation. -> x = -2y+4 and 3x+2y=0

Then you would plug in the x into the x in the second equation -> 3(-2y+4)+2y=0

Then simplify it -> -6y+12+2y=0 -> -4y+12=0 ->   -4y = -12   ->  -4y/-4= -12/-4  -> y=3

Then plug the y into the other equation to find x -> x+2(3)=4 -> x+6=4  ->  x=-2

Then plug the x and y into an equation to see if it works : -2+2(3)=4  -> (It works)

Some more examples: