Question

Verify that( a+b)+c=a+(b+c) where a=-1/2 b=3/4 c=5/7​

Answer 1

Explanation:

`(a + b) + c \\ = \bigg(- (1)/(2) + (3)/(4) \bigg ) + (5)/(7) \\ = \bigg(- (2)/(4) + (3)/(4) \bigg ) + (5)/(7) \\ = (1)/(4) + (5)/(7) \\ = (7 + 20)/(28) \\ \red{ \bold{\therefore \: (a + b) + c= (28)/(28)}}...(1) \\ \\ a + (b + c) \\ = - (1)/(2) + \bigg( (3)/(4) + (5)/(7) \bigg) \\ = - (1)/(2) + \bigg( (21 + 20)/(28) \bigg) \\ = - (1)/(2) + (41)/(28) \\ = ( - 14 + 41)/(28) \\ \red{ \bold{a + (b + c) = ( 27)/(28)}}....(2) \\ \\ from \: equations \: (1) \: and \: (2) \: it \: is \\ obvious \: that: \\ \: \: \: \purple{ \boxed{\bold{ (a + b )+ c = a + (b + c) }}} \\ \: \: \: hence \: verified.`