Answers

2014-11-18T15:10:34+08:00
Elimination method?

Let's do it like this

Align the two equation

   7x  - 4y =  19
+17x - 2y  = -31
-------------------------

Let's begin with

19 + (-31)

unlike terms will be subtracted and take the sign of the bigger number

So it will be -12

Next

-4y + -2y

Like terms will be added and copy the sign of the two

So it will be -6y

Lastly,

7x + 17x

Add

So it will be 24x

We may now combine the three

24x - 6y = -12

That's it

We may divide all by 6 to simplify

(24x - 6y)/6 = -12/6

So it will be

4x - y = 2

That's it again

I hope it helps
0