Answered

Suriin ang IDNStudy.com para sa mabilis at kaugnay na mga sagot. Magtanong ng anumang bagay at makatanggap ng kumpleto at eksaktong sagot mula sa aming komunidad ng mga propesyonal.

How to prove the following using the Order properties of Real Numbers?
1.If a,b element of Real number and a<b,then a<a+b/2<b.
2.If a<b and c<d,then ad+bc < ac+bd.

Sagot :

Chayieegaloidn
set examples. 
1. a<b , a<a+b/2<b 
   = a<a+b/2                                              = a+b/2<b 
   = 2a < 2a + b                                         = 2a +b <b
   = 2a -2a <b                                            = 2a<0
   = 0 < b                                             
which doesnt prove anything. so lets set examples. 
say for example a= -5 , b= -4 
-5<-5+-2<-4
-5<-7<-4  ,   -5 is not less than -7 it is more than -7 
hence, <b , a<a+b/2<b is not always true. 

2. a<b and c<d then ad+bc < ac+bd 
   = ad-ac<bd-bc
   = a(d-c)<b(d-c) 
   = a < b which is stated in the above statement.