How do you solve 2x – y = –2 and x = 14 + 2y?

Question

2140 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-11T11:27:35

#{(x = -6), (y=-10) :}#

Your system of equations looks like this

#{(2x-y = -2), (x = 14 + 2y) :}#

To solve this system by substitution, use the value of #x# from the second equation to find the value of #y# in the first equation.

#2 * (14 + 2y) - y = -2#

#28 * 4y - y = -2#

#3y = -30 implies y = (-30)/3 = color(green)(-10)#

Now take this value back to the second equation and find #x#

#x = 14 + 2 * (-10)#

#x = 14 - 20 = color(green)(-6)#

The two solutions to your system of equations are

#{(x = -6), (y=-10) :}#