How do you solve the system 3x - 2y = 8 and 2x + 5y = -1?

1 Answer
Jun 25, 2017

Answer:

#x=2, y=-1#

Explanation:

This is a clear simultaneous equation.

#3x-2y=8#
#2x+5y=-1#

In order to solve this, either the x's or the y's must be balanced. It does not matter which one you start with.

For this, I'll balance the y's:

#15x-10y=40# Every value is multiplied by 5.
#4x+10y=-2# Every value is multiplied by 2.

Both y values can now be eliminated.

#15x-10y+4x+10y=19x#
#40-2=38#

#19x=38#

Now solve for x.

#x=38/19=2#

Put the value for x back into either equation to find y.

#3x-2y=8#
#3(2)-2y=8#
#6-2y=8#
#-2y=8-6=2#

Rearrange to find y.

#-2y=2#

Divide both sides by -2.

#y=2/-2#

#y=-1#