What is the solution of the system #y=x-10, y=2x+5#?

1 Answer
EZ as pi
Nov 12, 2016

#x = -15 and y = -25#

Explanation:

This is a perfect scenario for solving the two equations.
(which represent straight lines and the solution gives the point of intersection.)

#color(blue)(y = x-10)" and "color(red)(y = 2x+5)#

The two #y-# values are equal!

#color(white)(xxxxxxxxxxxxx)color(blue)(y) = color(red)(y)#

Therefore:#color(white)(xxx)color(blue)(x-10) =color(red)(2x+5)#

#color(white)(xxxx.xxx)-10-5 =2x-x#

#color(white)(xxxx.xxx)-15 =x" "larr# we have the x-value

#y = (-15)-10 = -25" "larr# from the first equation

Check in the second equation:

#y = 2(-15)+5 = -25#

#x = -15 and y = -25#

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