Question

Exercitiu 3 va rog ajutati'ma dau 81 de puncte

Answer 1

a) ( 2 + 1/4) · 2 /5 = ( 4·2 /4 + 1/4) · 2 /5 = ( 8 /4 + 1 /4) · 2/5 = 9 /4 · 2/5 =
     = 9/10= 0,9

b) 1/4 · ( 2 + 3 · 2) = 1/4 · ( 2 + 6) = 1/4 · 8 = 2
c) ( 1·6/12 + 2·4/12 - 1·3/12) : 11/120 = ( 6/12 + 8/12 - 3/12) · 120/11 =
   =( 6 + 8 - 3) /12 · 120/11 = 11/12 · 120/11 = 10
d) ( 1·4/12 + 5·2/12 - 3·3/12) : 7/300 = ( 4 +10 - 9)/12 · 300/7 = 5/12 · 300/7 =
   = 25·5/7 = 125/7
e) ( 2·14/70 + 1·10/70 - 1·5/70) · 91/3 = ( 28 + 10 - 5)/70 · 91/3 = 33/70 · 91/3 =
   = 11·91/70 = 1001/70
f) 24 · ( 1·12/24 + 1·4/24 + 1·3/24) = 24 · ( 12 + 4 + 3)/24 = 24 · 19/24 = 19
g) 3 -3 : ( 3 ·4/4 + 3/4) = 3 - 3 : ( 12/4 + 3/4) = 3 - 3 : 15/4 = 3 - 3 ·4/15 = 3 - 4/5 
   = 3·5/5 - 4/5 = 15 - 4/5 = 11/5
h) 3/2 - 1/3 : ( 1/3 + 1/5) = 3/2 - 1/3 : ( 5 + 3)/15 = 3/2 - 1/3 : 8/15 = 3/2 - 1/3 · 15/8 = 3/2 - 5/4 = 6 -5/4 = 1/4
i)1/2 -1/2 : ( 1·6/6 + 1·3/6 - 1·2/6) = 1/2 -1/2 : ( 6+ 3 - 2)/6 = 1/2 - 1/2 : 7/6 =
  = 1/2 - 1/2 · 6/7 = 1/2 - 3/7 = 7 - 6 /7 = 1/7