Answer:
#1:
![4x - 15 + 2x + 3 = 48\\\\2x + 18 = 48\\\\2x = 30\\\\x = 15](https://img.qammunity.org/2021/formulas/mathematics/college/ug18z6qfqffcmn5wc2i4xk8e36x2jdaibk.png)
#2:
Part 1: Solve for x
![6x - 7 = 5x + 1\\\\x - 7 = 1\\\\x = 8](https://img.qammunity.org/2021/formulas/mathematics/college/x0296ptvce1guicna12g6n5700xuhmpz2w.png)
Part 2: Plug in x for PQ
![6(8) - 7\\\\48 - 7\\\\41](https://img.qammunity.org/2021/formulas/mathematics/college/v7knfdqktfaulj1ghfkuxn7563fftpfvta.png)
The length of segment PQ is 41.
Part 3: Plug in x for QR
![5(8) + 1\\\\40 + 1\\\\41](https://img.qammunity.org/2021/formulas/mathematics/college/xu28a7wwc92lrmn76duj15wfhrd4naq391.png)
The length of segment QR is 41.
Part 4: Length of PQ + length of QR = length of PR
PQ + QR = PR
41 + 41 = PR
82 = PR
The length of segment PR is 82.