First we have to find out what p and q are. We have system of equations and elimination looks good here.
7p + 5q = 2
8p - 9q = 17
------Let's eliminate q
9[7p + 5q = 2]
5[8p - 9q] = 17
------
63p + 45q = 18
40p - 45q = 85
------add
103p = 103
p = 1
====== Shove that back into the to original equation.
7(1) + 5q = 2
5q = - 5
q = - 1
======Now, to find what... - p + 14 q =
- 1 + 14(-1) =
= - 15
======The final answer.
( Forgot to mention that both the answers 1 and - 1 satisfy the original system of equations )
