Question

Calculati: a)1/2+2/3:4/9 c)2:(2/3)^2+11/5:11/10 e)12,9+1,8*7 g)(0,25)^7*(0,25)^14:(1/4)^19+ +0,125 b)12+4/5:(1/2-1/3) d)(1/4+7/6)*15/34+3/2*(1/3-1/21) f)3+37:(1,8+0,(6))
h)0,5(1/3+1/4-0,1(6)):2,5

Answer 1

~impartirea se transforma in inmultire cu inversul

a) 1/2+2/3 : 4/9=
1/2 +2/3 * 9/4 =
1/2 + 3/2=
4/2=2

b) 12+ 4/5:(1/2-1/3)=
12+ 4/5 :[ (3-2)/6]=
12 + 4/5 : 1/6 =
12 +4/5* 6/1=
12 + 24/5 =
60/5+24/5= 84/5

c) 2: (2/3)^2  + 11/5 : 11/10 =
2 : 4/9 +11/5 * 10/11 =
2 * 9/4 +2 =
9/2 +2 =
9/2+4/2= 13/2

d)(1/4+7/6)* 15/34 +3/2*(1/3-1/21)=
[ (3+14)/12] *15/34+ 3/2 * [(7-1)/21]
= 17/12*15/34 + 3/2 * 6/21=
255/408 +3/7

e) 12,9+ 1,8*7=
 12,9+ 12,6= 25,5 =
255/10 =51/2

f)  3+37:(1,8+0,(6))=
3+37:(18/10+6/9)=
3+37:[(18*9)/90+(6*10)/90]=
3+37:(162/90+60/90)=
3+37: 222/90 =
3+37*90/222=
 3+15=18

g)  0,25=1/4
Cand au acelasi exponent puterile se : -> aduna (la inmultire)
                                                               ->scad (la impartire)
(0,25)^7*(0,25)^14:(1/4)^19+0,125=
 (0,25)^21: (0,25)^19+0,125=
 (0,25)^2+0,125 =
0,0625+0,125=0,1875

h) 5/10 * (1/3 +1/4-0,1(6)):25/10 =

5/10*10/25 * (1/3+1/4+ 15/90)=  
1/5*( 1/3+1/4-1/6)=
1/5 [(4+3-2)/12]=
1/5 * 5/12= 1/12