SOLUTION: what is the solution of the system using matrix? 4x+4y=40 -4x-3y=-32 thank you for your time.

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Question 916057: what is the solution of the system using matrix?
4x+4y=40
-4x-3y=-32
thank you for your time.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
4x%2B4y=40
-4x-3y=-32+
_________________

STEP 1:
Find coefficient matrix (D), X matrix (Dx) and Y matrix (Dy).
In this example we have:
D = %28matrix%282%2C2%2C+4%2C4%2C+-4%2C-3%29+%29
Dx=%28matrix%282%2C2%2C+40%2C4%2C+-32%2C-3%29+%29
Dy=%28matrix%282%2C2%2C+4%2C40%2C+-4%2C-32%29+%29

STEP 2: Find determinants for D, Dx and Dy.

det D= %28matrix%282%2C2%2C+4%2C4%2C+-4%2C-3%29+%29=4%2A%28-3%29-4%28-4%29=-12%2B16=4
det Dx= %28matrix%282%2C2%2C+40%2C4%2C+-32%2C-3%29+%29=40%28-3%29%2A1-4%2A%28-32%29=-120%2B128=8
det Dy= %28matrix%282%2C2%2C+4%2C40%2C+-4%2C-32%29+%29 =4%2A%28-32%29-40%2A%28-4%29=-128%2B160=32


STEP 3: Solve for the x and y

x=D%28x%29%2FD=8%2F4=highlight%282%29
y=D%28y%29%2FD=32%2F4=highlight%288%29