A student determined that the ordered pair 1 4 is a solution
A student determined that the ordered pair (1. 4) is a solution ol the following system x+y=-3 5x + y = 3 His icasoinng was that the orderod pax satisfies the fust equation x + y = - 3, since 1 + (- 4) = - 3 What went wrong? The ordered pair (1, - 4) is not a solution of the system because the ordered pair must bo in quadrant II The ordered pair (1, - 4) is not a solution of the system because the ordered pair must be on the x axis The ordered pair (1, - 4) is not a solution of the system because the ordered pair must bo on the y-axis The ordered pair (1, - 4) is not a solution of the system because it is not a solution of the second equation
Solution
Given : x + y = - 3...........(1)
5x + y = 3..........(2)
ordered pair ( 1,-4)
so, by the eqn (1)
putting the ordered pair (1, -4) as x = 1 and y = -4 , we get:
1 - 4 = - 3
-3 = -3
that satisfies the equation.
now,
putting the ordered pair in eqn (2), we get:
5*(1) + (-4) = 3
5 - 4 = 3
1 = 3
that not satisfies the equation.
Hence it is clear that the point (1,-4) is the solution of x + y = - 3 but not the solution of 5x + y = 3
so, the ordered pair ( 1,-4) is not a solution of the system because it is not a solution of the second equation. Hence option (D) is the correct answer.
