Question

Which ordered pair is the solution to the system of equations?
x+y=-1
x-3y=11
A.
(2, −3)

B.
(−2, 1)

C.
(5, −2)

D.
(−6, 5)

Answer 1

I have a calculator that does that its called a TI-36XPro. The answer is A.

Answer 2

The "solution" to a system of equations basically means an ordered pair that makes both equations true when you put it into the equation.  In other words, a value that works!  So let's try it.

A is (2, -3).  x is 2, y is -3.  x+y=-1.  2+(-3)=-1.  2-3=-1.  -1=-1.  This works!  But it needs to work in BOTH equations, so let's try that.  x-3y=11.  2-3(-3)=11.  2+(-3*-3)=11.  2+9=11.  11=11!  This is TRUE, so A is correct!!

Answer: A (2, -3)