Question

Calculati :
a. [(1/3+ 2/21) :(1/18+1/14) - s intregi si 1/2] ×8
b. (1/12+1/24-1/36) : ( 1/4 + 3/5) × 2 intregi si 3/7
c. (3+3/8) : ( 4/35 - 2/70 ×7/4) ×4/15

Answer 1

b. (1/12+1/24-1/36) : ( 1/4 + 3/5) × 17/7=
[(6+3-2)/72]:[(5+3x4)/20]x17/7=
7/72:17/20x17/4= 
7/72x20/17x17/4=simplif cu 17 si 2=
7/36x10/1x1/4=simplif.cu 2=7/18x5/4=35/72
c. (3+3/8) : ( 4/35 - 2/70 ×7/4) ×4/15=
[(3x8+3)/8]:[(4/35-2/40)]x4/15=
27/8:(4/35-1/20)x4/15=
27/8:[(4x4-7)/140]x4/15=
27/8:9/140x4/15=simplif cu 4 si 3
27/8:3/35x1/5=
27/8x35/3x1/5=simplif.cu 5 si 3=
9/8x7/1=63/7=9