How do you find the inverse of $A=$ $((18, -3), (-3, 15))$ ?

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Answer 1 · 2016-02-21T16:37:38

To find the inverse $A^-1$ of a matrix $A$ which is $2x2$ the formula is

$[((a, b), (c, d))]^(-1)=1/[a*d-b*c]*[((d, -b), (-c, a))]$

Just replace for $a=18,b=-3,c=-3,d=15$ to get

$A^-1=1/87*((5,1),(1,6))$

How do you find the inverse of A=A=((18, -3), (-3, 15))((18, -3), (-3, 15))?