Question

Which pair of lines intersects at
(
2
,
−
1
)
?

A.
{
2
x
+
4
y
=
0
2
x
−
y
=
0

B.
{
4
x
+
2
y
=
0
3
x
+
y
=
−
1

C.
{
2
x
+
4
y
=
0
3
x
+
y
=
5

D.
{
3
x
−
y
=
5
2
x
+
y
=
5

Answer 1

C

Check (2, −1) in option C:
2(2) + 4(−1) = 4 − 4 = 0
3(2) + (−1) = 6 − 1 = 5

Both equations hold, so the lines in C intersect at (2, −1).