SOLUTION: Solve using the multiplication principle first. Then use the elimination method: 7p+5q=2 8p-9q=17

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Solve using the multiplication principle first. Then use the elimination method: 7p+5q=2 8p-9q=17       Log On


   

Question 376296: Solve using the multiplication principle first. Then use the elimination method:
7p+5q=2
8p-9q=17

Found 2 solutions by user_dude2008, checkley79:
Answer by user_dude2008(1862) About Me  (Show Source):
You can put this solution on YOUR website!
7p+5q=2
8p-9q=17


63p+45q=18
40p-45q=85


103p=103
p=1

7p+5q=2
7(1)+5q=2
7+5q=2
5q=-5
q=-1

Answers: p=1, q=-1

Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
7p+5q=2 multiply by 8
8p-9q=17 multiply by -7 & add.
56p+40q=16
-56p+63q=-119
-----------------
103q=-103
q=-103/103
q=-1 ans.
7p+5*-1=2
7p-5=2
7p=5+2
7p=7
p=7/7
p=1 ans.
Proof:
8*1-9*-1=17
8+9=17
17=17