(a) `x + y = 4`
`{:(x,-2,-1,0,1,2,3,4),(y = 4 -x,6,5,4,3,2,1,0):}`
Some of the ordered pairs which satisfy the equation `x + y = 4 " are " (-2, 6), (-1, 5), (0, 4), (1, 3), (2, 2), (3, 1), (4, 0)`
`{:(x,-2,-1,0,1,2,3,4,5),(y = x -2,-4,-3,-2,-1,0,1,2,3):}`
`:.` Some of the ordered pairs which satify the equation `x -y =2 " are " (-2, -4), (-1, -3), (0,-2), (1, -1), (2, 0), (3, 1), (4, 2), (5, 3)`
From the above graph, we notice that the two given equation intersect at the point (3, 1).
That is, `x + y = 4 and x - y = 2` have a common point, (3, 1). Therefore, (3,1) is the solution of the equation `x + y = 4 and x -y =2`
Verification:
`x + y = 4` (1)
`x -y = 2` (2)
Solving Eqs. (1) and (2), we get, `x = 3 and y =1`
`:.` (3,1) is the solution of `x + y = 4 and x - y = 2`
