Question

Le vreau si eu pe 7 si pe 8 va rog. Mulțumesc!

Answer 1

8) a= suma Irinei, b= suma Andreei
a+b=1430
b=a + (20/100)*a = a+a/5 = 6a/5
a+6a/5 = 1430 => 11a =7150 => a=7150/11 = 650
b=6*650/5 = 780
Verificare : 650+780=1430
7) 1/4*8/3 = 2/3 ; 6/7*8/3 = 16/7 ; 1/4*14/9 = 7/18 ; 14/9*6/7 = 12/9
3/8 :5/4 = 3/8*4/5=3/10 ; 3/8:3/2 = 3/8 * 2/3 = 1/4 ;
5/12:5/4 = 5/12*4/5 =1/3; 5/12:3/2=5/12*2/3=5/18
a=3/5 => a patrat = 9/25 ; a la a treia = 27/125
a=4/6 =2/3 => a patrat = 4/9 ; a la a treia = 8/27
a=800 => 5*800/100=40 ; 120*800/100 = 960 ; 240*5/100=12; 240*120/100=288
Succes.