Question

Vă rrrrrrroooooooggggg

Answer 1

21)a)(13/5-3/5)-(4/6+7/6-5/6)+18/9=10/5-6/6+18/9=



Dam numitor comun 270(5x6x9)....amplificam 10 cu 54,pe 6 cu 45 si pe 9 cu 30 si avem
(540-270+270)/270=540/270 simplificam cu 270 si obtinem rezultat final 2

B)(1/3+2/4+3/5-4/6+10/100)×0+3/4-2/4=0+3/4-2/4=1/4


Orice numar/fractie inmultita cu 0 da 0
C)(1+4/2+9/3)-8/8=(6+12+18)/6-8/8=36/6-8/8=(288-48)/48=240/48=5



22)7/5-(8/5-@)=2/5
7/5-2/5=8/5-@
5/5=8/5-@
@=8/5-5/5
@=3/5
Verificare 7/5-(8/5-3/5)=2/5
7/5-5/5=2/5
2/5=2/5

B) 8/3+4/3-(@+3/3)=8/3
12/3-8/3=@+3/3
4/3-3/3=@
@=1/3

Verificare 8/3+4/3-(1/3+3/3)=8/3
12/3-4/3=8/3
8/3=8/3


C)2/5+[2/5+(2/5-@)]-1/5=3/5
2/5+[2/5+(2/5-@)]=3/5+1/5
2/5+(2/5-@)=4/5-2/5
2/5-2/5=2/5-@
@=2/5
Verificare 2/5+[2/5+(2/5-2/5)]-1/5=3/5
2/5+2/5+0-1/5=3/5
3/5=3/5


23)a)(2+3+4+5+6+7+8+9+10-1-2-3-4-5-6-7-8-9)/10=9/10 adevărat
2+3=5+4=9+5=14+6=20+7=27+8=35+9=44+10=54-1=53-2=51-3=48-4=44-5=39-6=33-7=26-8=18-9=9

B) (2/6+2/8+2/10)-(2/6+2/8+2/10)=0
Simplificam cu 2
(1/3+1/4+1/5)-(1/3+1/4+1/5)=0
Dam numitor comun 60 si impartim pe 60 la 3,4,5 si avem (20+15+12)/60-(20+15+12)/60=0
47/60-47/60=0 adevărat