Using properties of determinants prove that:



[R1’ = R1 + R2]


[R1’ = R1/(a + b)]


[R2’ = R2 + R3]



[R2’ = R1/(b + c)]


[R1’ = R1 + R2]


= (a + b)(b + c){0 + 2( - b + a + b + c) + 0} [expansion by first row]


= 2(a + b)(b + c)(c + a)


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