How do you solve this system of equation: #y = -6 and y = - 2x - 6#?

2 Answers
Nov 1, 2017

#(x,y)=(0,-6)#

Explanation:

If
[1]#color(white)("XXX")y=-6#
and
[2]#color(white)("XXX")y=-2x-6#

Using [1] we can substitute #-6# for #y# in [2]
[3]#color(white)("XXX")-6=-2x-6#
then add #6# to each side
[4]#color(white)("XXX")0=-2x#
and finally divide both sides by #(-2)#
[5]#color(white)("XXX")0=xcolor(white)("xxxxxx")#...or, equivalently, #x=0#

Nov 1, 2017

#(x,y)=(0,-6)#

Explanation:

#color(blue)(rarry=-6# #("equation 1")#

#color(blue)(rarry=-2x-6# #("equation 2")#

As we know that #y=-6#, we can sub substitute it in equation #2#

#rarr-6=-2x-6#

#rarr-2x=cancel(-6+6#

#rarr-2x=0#

#color(green)(rArrx=0#

So we can say that

#color(purple)((x,y)=(0,-6)#

Hope this helps!!! ☺☻