Question

What is the solution to the linear system of equations?
x + 4y = –8
x – y = 7




A.


(4, –3)


B.
(4, 3)


C.
(7, 0)


D.
The system has no solution.

Answer 1

By rewriting eq.2:
\[y = x - 7\]
and by plugging this expression into eq.1 we get:
\[x +4*(x-7) = -8\]
and the solution is:
\[x = 4; y = -3\]
so the answer is a) (4;-3)

Answer 2

and the above result fits in exactly with the graph (it's the coordinates of the intersection of the two lines)

Answer 3

oh ok. i get it now. thx so much.