Question

4. Să se calculeze :100×[8,4-3,2×(7,2÷5-1,2 la a doua)]
5

Answer 1

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

b)1/12+4/5:(1/2-1/3)=
=1/12+4/5:[3/6-2/6]
=1/12+4/5:1/6
=1/12+4/5 ×6
=1/12+24/5
=5/60+288/60
=293/60=
=4,88(3)


c) 2:(2/3)²+11/5:11/10=
=2: 4/9+11/5 ×10/11=
=2 ×9/4+2=
=9/2+2=
=(9+4)/2=
=13/2=
=6,5

d) (1/4+7/6)*15/34+3/2*(1/3-1/21)=
=(3/12+14/12)*15/34+3/2*(7/21-1/21)=
=17/12 *15/34+3/2*6/21=
=1/12 *15/2+3/7=
=15/24+3/7=
=5/8+3/7=
=(35+24)/56=
=59/56
e) 12,9+1,8*7=
12,9+12,6=
=25,5

f. 3+37/[1,8+6/9] =
=3+37/[1,8+2/3]
=3+37/[18/10+2/3]
=3+37/[9/5+2/3]
=3+37/[27/15+10/15]
=3+37/37/15
=3+37·15/37
=3+15=
=18

 g) (0,25)⁷ * (0,25)¹⁴:(1/4)¹⁹+ 0,125=
= (1/4)²¹:(1/4)¹⁹+ 125/1000=
= (1/4)²+ 1/8=
=1/16+1/8=
=(1+2)/16=
=3/16 =
=0,1875

h)0,5*[1/3+1/4-0,1(6)]:2,5=
0,1(6)=(16-1)/90=15/90=1/6
h)0,5*[1/3+1/4-0,1(6)]:2,5=
=0,5*(1/3+1/4-1/6):2,5=
=0,5*(4/12+3/12-2/12):2,5=
=5/10 * 5/12 :25/10=
=1/2 * 5/12 × 2/5=
=1/2 * 5/12 × 2/5=
=1/12 =
=0,08(3)

 i) 6+11/5:(2 2/3-1 1/5)+1:[(5/3+1/7-2/21)*1/6]=
= 6+11/5:(8/3-6/5)+1:[(35+3-2)/21*1/6]=
= 6+11/5:(40-18)/15+1:(36/21*1/6)=
= 6+11/5 :22/15+1: 6/7=
= 6+11/2 × 15/22 +7/6=
=6+3/2+7/6=
=6+(9+7)/6=
=(36+16)/6=
=52/6=
=26/3=
=8,(6)

j) [(3/5)⁷:(2-1 2/5)⁴+5:1 1/4 -(3//5)³]:1 3/5=
=[(3/5)⁷:(2-7/5)⁴+5:5/4 -(3/5)³]:8/5=
=[(3/5)⁷:(3/5)⁴+4 -(3/5)³]:8/5=
=[(3/5)³+4 -(3/5)³]:8/5=
=4:8/5=5/2

k)[(1/2+2/3+5/6):12/7-6*1/18]*1/4:(5*12/25-1 1/3)=
=[(3+4+5)/6 ×7/12-1/3]*1/4:(12/5-4/3)=
=(12/6 ×7/12-1/3)*1/4: (36-20)/15=
=(7/6-1/3)*1/4: 16/15=
=(7-2)/6*1/4 × 15/16=
=5/6*1/4 × 15/16=
=5/24 × 15/16=25/128

l){2+2 1/2-2/3*[0,(1)+0,(2)]}:3,1(6)=
3,1(6)=(316-31)/90=285/90=19/6
0,(1)=1/9
0,(2)=2/9
 l) {2+2 1/2-2/3*[0,(1)+0,(2)]}:3,1(6)=
= [2+5/2-2/3*(1/9+2/9)]:19/6=
=[(4+5)/2-2/3*1/3]:19/6=
=[9/2-2/9]:19/6=
=[(81-4)/18]:19/6=
=77/18 × 6/19 =
=77/57

m){8/35+[(3/2-33/35)+(3/14-2/35)-(2-12/7+5/14)]}*3 1/3=
={8/35+[(105-66)/70+(15-4)/70-(2/7+5/14)]}*10/3=
={8/35+[39/70+11/70-(4+5)/14)]}*10/3=
={8/35+[50/70-(4+5)/14)]}*10/3=
=[8/35+(5/7-9/14)]*10/3=
=[8/35+(10-9)/14)]*10/3=
=(8/35+1/14)*10/3=
=(16+5)/70*10/3=
=21/70 *10/3=
=3/10 * 10/3=1
 
n)0,0(6)+15/64*1,28-2*[0,125-0,08(3)]=
0,0(6)=6/90=3/45=1/15
0,08(3)=(83-8)/900=75/900=5/60=1/12
n)0,0(6)+15/64*1,28-2*[0,125-0,08(3)]=
=1/15+15/64*128/100-0,25+1/6=
=1/15+15/1*1/50-0,25+1/6=
=1/15+3/10-1/4+1/6=
=(4+18-15+10)/60=
=17/60