Question

let a,b,c be any three rational numbers where a=2/3,b=4/5,c=-5/6. verify that (a+b)+c=a+(b+c)​

Answer 1

Answer:

Step-by-step explanation:

a=2/5

b= 4/5

c= -5/6

put value of a b c in [ a+b]+c= a+[b+c]

[2/5+4/5]-5/6=2/5+[4/5-5/6]

6/5-5/6=2/5+[20/30-25/30]

36/30-25/30=2/5-5/30

11/30=12/30-5/30

11/30=11/30

hence proof

therefor [a+b]+c=a+[b+c]

Answer 2

Answer:

let,

a=2/3

b=4/5

c=-5/6

According to question.

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

L.H.S

(2/3+4/5) +(-5/6)

22/7-5/6

132-75/90

= 57/90 =19/30

R.H.S

2/3+{4/5+(-5/6)}

2/3+(4/5-5/6)

2/3+(24-25/30)

2/3+ (-1/30)

60 -3/90

= 57/90 = 19/30