How do yo solve this difficult problem of Equations?

If you have this equation

Find "x+y"enter image source here

1 Answer
Aug 12, 2018

#x+y=6#

Explanation:

#2x+y=9to(1)#

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

#"multiply equation "(1)" by 2"#

#4x+2y=18to(3)#

#"add "(2)" and "(3)" term by term"#

#(3x+4x)+(-2y+2y)=(3+18)#

#7x=21#

#"divide both sides by 7"#

#x=21/7=3#

#"substitute "x=3" into equation "(1)#

#6+y=9rArry=9-6=3#

#"solution is "(x,y)to(3,3)#

#"hence "x+y=3+3=6#