Question

Solve each system of equation by using elimination 9p+8q=2 6p-5q=26

Answer 1

You need to find a number which either has 6 and 9 as factors or 8 and 5 as factors.

I will go with 18

9p + 8q = 2 —> to get to 18p you have to multiply 9 by 2 so multiply the whole equation by 2

6p - 5q= 26 —> to get to 18p you have to multiply 6 by 3 so multiply the whole equation by 3

You end up with:

18p + 16q = 4

And

18p -15q = 78

Since they both now have a common term (18p) you can subtract them from one another by elimination to have 1 unknown left in the equation.

18p + 16q = 4
- 18p - 5q = 78

Goes to 21q ( - and - is a +) = -74
So q=-74/21

When this is substituted in original equations (ideally the easier one)

9p = 2-8(-74/21)
You will obtain p through division by 9