Question

Stiind ca a+1+b=140,Calculeaza: a) a+(1+b)=
b) a+(1+b)+(1+b)+a=
c) (2+a)+(1+b)+6+(1+b)+a=

Answer 1

a + 1 + b = 140 ⇒ a + b = 140 - 1 ⇒  a + b = 139 

a)  a + ( 1 + b ) = a + 1 + b = 140  → adunarea este asociativa 

b)  a + ( 1 + b ) + ( 1 + b ) + a = ( a + 1 + b ) + ( a + 1 + b ) = 140 + 140 = 280

c) ( 2 + a ) + ( 1 + b ) + 6 + ( 1 + b ) + a = 288 
= ( a + 1 + b ) + ( a + 1 + b ) + 2 + 6 = → asociativitatea adunarii 
= 140 + 140 + 8 =
= 288