Respostas

2014-06-30T17:16:08-03:00

a) P+Q+R = (a+b+c)+(a-b-c)+(a+b-c) = a+b+c+a-b-c+a+b-c = 3a+b-c

b) P+Q-R = (a+b+c)+(a-b-c)-(a+b-c) = a+b+c+a-b-c-a-b+c = a-b+c

c) P-Q+R = (a+b+c)-(a-b-c)+(a+b-c) = a+b+c-a+b+c+a+b-c = a+3b+c

d) P-Q-R = (a+b+c)-(a-b-c)-(a+b-c) = a+b+c-a+b+c-a-b+c = -a+b+3c



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