Question

Linear Algebra,

So I have to find the unknown variables in this system:

http://screencast.com/t/RlTeC5F35y

Answer 1

a + 2b = 4
2a - b = -2
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Answer 2

before adding them together, you need to massage the coefficients a bit

Answer 3

"massage"? hehe

Answer 4

a+2b=4
a=(4-2b)

2(4-2b)-b=-2
8-4b-b=-2
8+2-5b=0
10-5b=0
10=5b
b=2

if a+2b=4
a+2*2=4
a=0

Answer 5

My bad, it was a mistake in my end lol ty