How do you solve the system of equations #5x - 2y = 32# and #x + y = - 9#?

1 Answer
Peter E.
Mar 30, 2017

#x=2# and #y=-11#
BUT READ WHY :)

Explanation:

Okay so basically we start by putting both of the equations next to each other.

So...

#5x - 2y = 32#

#x + y = -9#

For this one, I'd use the substitution method, so...

#x + y = -9 #

y= -9 - x

Now that we've got that, we can plug it into the top equation for y...

#5x - 2(-9 - x) = 32#

#5x+18+2x=32#

#7x + 18 = 32#

#7x = 14#

#x=2#

Now we solve in terms of y, using 2 for x...

#2 + y = -9#

#y=-11#

Now we have

#x=2# and #y=-11#

Of course, don't forget to check ;)

#5(2)-2(-11)=32#

#10+22=32#

#32=32#

It checks! Make sure you understand what you're doing, don't just copy because I won't be here during your test! Leave a comment if you need further help!

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