# maths

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Write the system as a matrix equation and solve using inverses.

x1 + 2x2 - x3 = -3
-2x1 - x2 + 3x3 = 0
-4x1 + 4x2 - x3 = -12
A. x1 = 2, x2 = -3, x3 = 1
B. x1 = 1, x2 = -2, x3 = 1
C. x1 = 1, x2 = -2, x3 = 0
D. x1 = 1, x2 = -3, x3 = 1

• maths -

this one seems difficult...plz help

• maths -

You have an equation AX=B
where
A =
(1 2 -3)
(-2 -1 3)
(-4 4 -1)
and
B =
(-3)
(0)
(-12)

A-1 = 1/3 times
(11 10 -3)
(14 13 -3)
(12 12 -3)

So, X = A-1B = (1,-2,0)

• maths -

fabulous

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