Answer:
a.
![x=27,y=13,z=9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a2hdzjc0j43dfipijpajxclbpx1nglz89c.png)
b. Yes, p || r.
Explanation:
a.
From the figure,
Since, p || q,
(∵ Alternate exterior angles are equal for parallel lines)
This gives,
![3x-3=4x-30\\4x-3x=-3+30\\x=27](https://img.qammunity.org/2020/formulas/mathematics/middle-school/30y4rf3t2ct2zjo17z76ty6w6kxw66qv16.png)
Now, q || r
∴
(∵ Corresponding angles are equal for parallel lines)
This gives,
![6y=4(27)-30\\6y=78\\y=13](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dnzplme1e6wbt7aiyqao214pd31lxw5v2w.png)
Now, since r is a straight line,
and
are supplementary angles.
![6y+6(z+8)=180\\6(13)+6z+48=180\\78+48+6z=180\\6z=180-(78+48)\\6z=54\\z=(54)/(6)=9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sksc8c107kobxqvc32f0gbk3aneneh4q7o.png)
Therefore,
.
b.
![3(x-1)=3(27-1)=3(26)=78\\6y=6* 13=78](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xsw4j3bgovgzd1qgvtuj7x8jdwiuot4rzt.png)
Since, alternate exterior angles
and
are equal, the lines p and r are parallel because, alternate exterior angles are equal only if two lines are parallel.