How do you solve the system of equations #x+y = 12# and #-10x+6y=-72#?

1 Answer
Apr 19, 2018

#y=3,x=9#

Explanation:

You can really do what method you want but for this time I'm going to use the subtraction method. Apply the following:

#x+y=12#
#-10x+6y=-72#

Now I extend the first term by 10.

#x*10+y*10=12*10= 10x + 10y = 120#.

Now take these terms plus eachother:

#10x+10y=120#
#-10x+6y=-72#

To get:

#16y=48#

Divide 16 on both sides to get

#y=3#

Now put that into:

#y+x=12#

To get:

#3+x=12#

Minus three on both sides to get

#x=9#

Check your work by putting them into the equations to see that they are accurate.

Hope this helps.