How do you solve x – y = 3 and 2x + 2y = 2?

2 Answers
Jun 14, 2018

Answer:

#(x,y)=(2,-1)#

Explanation:

From the first equation, #x=y+3#. Substitute in to the second:
#2(y+3)+2y=2#. Multiply this out: #2y+6+2y=2#. Collect terms: #4y=-4#, so #y=-1#.

Return to the first equation: #x-(-1)=3#, so #x=2#.

Jun 14, 2018

Answer:

#(x,y)to(2,-1)#

Explanation:

#x-y=3to(1)#

#2x+2y=2to(2)#

#"from equation "(1)tox=3+yto(3)#

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

#2(3+y)+2y=2#

#6+2y+2y=2#

#"subtract 6 from both sides"#

#4y=-4rArry=(-4)/4=-1#

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

#x=3-1=2#

#"point of intersection "=(2,-1)#
graph{(y-x+3)(y+x-1)=0 [-10, 10, -5, 5]}