Question

solve the following pair of linear equation 2 X + Y = 4 , 2X-Y=4 by substitution method ,elimination method ,multiplication method

Answer 1

by substitutional method,
2x - y=4 ------(1)
2x + y = 4--------(2)
by eq (2) ,
2x + y = 4
y = 4 - 2x
putting this value in eq (1)
2x - (4 - 2x) = 4
2x - 4 + 2x = 4
4x = 8
x = 2 ,
y= 4- 2x
y= 0
by elimination method ,
2x- y= 4
2x+ y= 4
--------------------
4x. = 8
x= 2
2x - y = 4
y= 0