Quadrilateral has vertices and

MATHEMATICS · Single correct · AoPS · Mathematics · Multi-Variable Linear Equations · Multi-Variable Linear Equations

Problem

Quadrilateral

PQRS

has vertices

P(1,4),\;Q(3,2),\;R(4,5)

and

S(5,1)

. Which vertex lies on both lines

x + y = 5

and

2x - y = 4

? (a)

P

(b)

S

(c)

Q

(d)

R