Question

va rog urgent,doar cele incercuite. sunt disperat......(12 13 14 15 21)​

Answer 1

Răspuns:

Explicație pas cu pas:

12) 1-10/100 = 1-1/10 = 9/10

9/10 - 9/10*20/100 = 9/10 - 9/10*1/5 =

(45-9)/50 = 36/50 = 72/100

Proc. = 72%

13) Suntem in cazul 12) :

1440/72*100 = 2000

14) x = salariul

12x/100 + 15/100(x+12x/100) = 720

1200x + 1680x = 720*100*100

1880x = 7200000

x = 2500

15)    y - 20y/100 = 88

100y - 20y = 8800

80y = 8800

y = 110

x + 10x/100 = 110

100x + 10x = 110*100

110x = 11000

x = 100   pret initial