I need help trying to understand how to solve each system by substitution here are my problems for homework tonight

x=y-8
-x-y=0

x+-2y+8
x+3y=12

y=-x-2
y=7x+2

x+-y+1
-4x+4y=12

x=7-2y
2x+y=5

:confused::confused:

x=y-8 You know that x= (y-8); Substitute (y-8) for X in the next equation

-x-y=0 This, when solved gives you the value of Y. Substitute this value for Y in the
next equation.

x+-2y+8 Remember that two negatives cancel each other. This, when solved, gives
x+3y=12 you the value of X. Plug both values into the 1st equations to check answer
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y=-x-2 Use the same procedure
y=7x+2

x+-y+1
-4x+4y=12
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x=7-2y Only the second equation gives a numerical value. Plug the value of X into
2x+y=5 this equation to solve the value of Y. Plug the value of Y into the first
equation to solve the value of X. (Plug = Substitute)