Răspuns:
Explicație pas cu pas:
9.
a) 15% * 80min = [tex]\frac{15}{100} * 80 = \frac{15*8}{10} = \frac{120}{10} = 12[/tex] min
b)15% * 120 kg = [tex]\frac{15}{100} *120= \frac{15*12}{10} = \frac{180}{10} = 18[/tex] kg
c) 15%* 650 lei= [tex]\frac{15}{100} * 650= \frac{15*65}{10} = \frac{975}{10} = 97,5[/tex] lei
d) 15%*200 m = [tex]\frac{15}{100} *200= \frac{15*20}{10} = 15*2= 30[/tex] m
10.
a) [tex]\frac{x}{6} * 480 =120\\
[/tex]
se simplifica 6 cu 480 prin 6 si ramane :
[tex]80x=120 <=> x=\frac{120}{80} = \frac{12}{8} = \frac{3}{2} [/tex]
b) [tex]\frac{x}{18} * 648 = 36[/tex]
se simplifica 18 cu 648 prin 18 si ramane:
[tex]36x=36 <=> x=1[/tex]
11.
a)
[tex]\frac{p}{100} * 640 = 80\\
\frac{64p}{10} = 80\\
\frac{32p}{5} = 80\\
32p= 400\\
p=\frac{400}{32} = \frac{100}{8} = \frac{25}{2} = 12,5 %[/tex]
p=12,5 %
b)
[tex]\frac{p}{100} * 1200 = 1600\\
12p =1600 |:4\\
3p=400\\
p=\frac{400}{3} = 133,(3) [/tex]
p=133,3%
12.
a) o ora are 60min
[tex]\frac{1}{3} * 60 = 20 min[/tex]
b)
o zi are 24 de ore
[tex]\frac{2}{3} * 24= 16 ore[/tex]
c)
un an are 12 luni
[tex]\frac{3}{4} * 12 = 9 luni[/tex]
13.
a)
un metru are 100 de cm
[tex]\frac{p}{100} * 100 = 15\\
p=15[/tex]
b)
o ora are 60min
[tex]\frac{p}{100} * 60= 10\\
\frac{6p}{10} = 10\\
6p=100\\
p=\frac{100}{6} = \frac{50}{3} = 16,6 [/tex]
p=16,6%
c)
luna februarie intr un an bisect are 29 de zile
[tex]\frac{p}{100} * 29 = 1\\p=\frac{100}{29} = 3,44 %[/tex]
p=3,44%
sper ca te am ajutat , coronita? :3
