Answer
(a)
Work Step by Step
z is the parameter, and can take any value.
x and y depend on z, so we check case by case:
$\left\{\begin{array}{llllll}
& & x=-z+4? & yes/no & y=-2z+5? & yes/no\\
& & & & & \\
a. & z=3, & 1=-3+4 & yes, & -1=-2(3)+5 & yes\\
b. & z=5, & 0=-5+4 & no & & \\
c. & z=0, & 4=-0+4 & yes, & -3=-2(0)+5 & no\\
d & z=7, & -1=-7+4 & no & &
\end{array}\right.$
Only case (a) satisfies both.
