Question 137269
x - y = 3
3x - 2y = 3

To solve this by substitution method.
First, change the subject of the fomulae in either equation.
This means... find the equation value of x or y (u can choose either)
 I will choose x-
Therefore equation 1 becomes-
x= 3+y

So by substitution method ,plug in 3+y for x in equation 2.

Therefore-
 3x-2y=3 will become .... 3(3+y)-2y = 3
 9+3y-2y=3
 3y-2y= 3-9 (by collecting like terms.
  y = -6

 To get our x value-
We have to substitute the value of y which is -6 in equation 1 (preferably).
 x-y=3
Plug in (-6) as y in this equation.
 x-(-6) = 3
 x+6 = 3
 x= 3-6
 x= -3
 You can use this approach to solve any equation of this type. But when u are using substitution approach u have to be very mindful of your signs rule.Adhere to it!
I hope this helps and Good luck!

Moruph Osuolale
mosuolal@uncc.edu