a) ( 23,4 - 6 i 3/20 ) : 2½ =17,25/2,5=6,9 b) 4 - [5/7 ×21/40+(0,25 + 2½)] ×2 - 1,875 =[105/280+2,75]*2= [0,375+2,75]*2=3,125*2=6,3 c) [ 4 ÷(1-5/5)-17,2 ]÷3 2/5 =[4÷0-17,2]÷3,4=-17,2÷3,4≈-5,05
a)( 23,4 - 6 i 3/20 ) : 2½ =(234/100-123/20)÷5/2=(234/100-615/100)*2/5=-381/100*2/5=-381/250 b) 4 - [5/7 ×21/40+(0,25 + 2½) ×2 - 1,875 =4-[3/8+(25/100+5/2)*2-1875/1000]=4-[3/8+(25/100+250/100)*2-1875/1000]=4-[3/8+5,5-1875/1000]=4-[375/1000+5500/1000-1875/1000]=4-4=0 c) [ 4 ÷(1-5/5)-17,2 ]÷3 2/5 =[4÷0-17,2]÷17/5=-172/10*5/17=-172/34
( 23,4 - 6 i 3/20 ) : 2½ =(23,4-6,15):2,5=17,25:2,5=6,9 4 - [5/7 ×21/40+(0,25 + 2½)] ×2 - 1,875 =[105/280+2,75]*2= [0,375+2,75]*2=3,125*2=6,3 [ 4 ÷(1-5/5)-17,2 ]÷3 2/5 =[4÷0-17,2]÷3,4=-17,2÷3,4≈-5,05
