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

2 Answers
Jul 9, 2018

Answer:

#x=-2,y=4#

Explanation:

Plugging the second equation

#y=-3x-2# in the first one:

#-3x-2x-2=8#
adding #2# on both sides and collexting like Terms

#-5x=10#

#x=-2# so #y=6-2=4#

Jul 9, 2018

Answer:

#(x,y)to(-2,4)#

Explanation:

#-2x+y=8to(1)#

#y=-3x-2to(2)#

#"equation "(2)" expresses y in terms of "x#

#"substitute "y=-3x-2" into equation "(1)#

#-2x-3x-2=8#

#-5x-2=8#

#"add 2 to both sides"#

#-5x=8+2=10#

#"divide both sides by "-5#

#x=10/(-5)rArrx=-2#

#"substitute "x=-2" into equation "(2)#

#y=6-2=4#

#"the point of intersection "=(-2,4)#
graph{(y+3x+2)(y-2x-8)=0 [-10, 10, -5, 5]}