I would use substitution
sub the 1st into the 2nd
4x - y = -2
4x - (2x) = -2
2x = -2
x = -1
then back into the first
y = 2x
y = 2(-1) = -2
Multi-Step Equations
Systems of Equation
2x = y
4x - y = -2
please help!!!!!
3 answers
thank you ....
2x + 4y = 24
x - 2y = -8
my mom tried helping me but didn't understand it....
2x + 4y = 24
x - 2y = -8
my mom tried helping me but didn't understand it....
For your second example I would use substitution again
Notice that in the second equation the x variable is all by itseld, that is, it is 1x understood.
That is the key.
look for a variable like that and solve for it
x - 2y = -8
x = 2y - 8
now sub that x value of (2y-8) into the other equation
2(2y-8) + 4y = 24
4y - 16 + 4y = 24
8y = 24 + 16
8y = 40
y = 40/8 = 5
now plug that into
x = 2y-8
x = 2(5)-8 = 2
so x=2, y=5
Notice that in the second equation the x variable is all by itseld, that is, it is 1x understood.
That is the key.
look for a variable like that and solve for it
x - 2y = -8
x = 2y - 8
now sub that x value of (2y-8) into the other equation
2(2y-8) + 4y = 24
4y - 16 + 4y = 24
8y = 24 + 16
8y = 40
y = 40/8 = 5
now plug that into
x = 2y-8
x = 2(5)-8 = 2
so x=2, y=5