Posted by **Chris** on Monday, January 14, 2008 at 4:40pm.

How do you solve this by linear combinations?

4x+3y=-8

3x-3y=15

- Math -
**mk-tintin**, Monday, January 14, 2008 at 5:02pm
L1 : 4x+3y=-8

L2 : 3x-3y=15

Do L1+L2--> 7x=7 so x=1

in L1 4*(1)+3y=-8

3y=-12

y=-4

the couple of solution is(1,-4)

- Math -
**DrBob222**, Monday, January 14, 2008 at 5:13pm
No. Add equation 1 (what mk-tintin labels L1) to equation 2, (L2) to obtain

7x +0y = -8+15

7x=7

x=1

- Math -
**mk-tintin**, Monday, January 14, 2008 at 5:14pm
doing L1+L2-->4x+3x+3y-3y=-8+15

--->7x=7

x=1

do u understand?

- Math -
**Michael**, Monday, January 14, 2008 at 5:17pm
Oh i was looking at it all wrong alright i understand it a bit better now, doh was plugging in the wrong numbers haha. Sorry.

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