How do you solve the system of equations: x+y=3, 2x-y= -3?

1 Answer
Aug 6, 2015

Answer:

Add the equations together to get an expression in terms o) #x#, solve for #x#, substitute the solution value back into one of the equations to solve for #y#
#color(white)("XXXX")##(x,y) = (0,3)#

Explanation:

[1]#color(white)("XXXX")##x+y=3#
[2]#color(white)("XXXX")##2x-y = -3#

Adding [1] and [2]
[3]#color(white)("XXXX")##3x = 0#
Solve for #x#
[4]#color(white)("XXXX")##x=0#

Substitute #0# for #x# in [1]# [5]#color(white)("XXXX")##0 + y = 3#
Solve for #y#
[6]#color(white)("XXXX")##y = 3#