Question

calculeaza in unitati de masura potrivite:
a)3\10 din 1 minut
4\5 din 1 ora
b)3\4 din 1 kg
9\10 din 1 tona
c)3\2 din 1 metru
8\5 din 1 cm
d)3\100 din 1 secol
4\10 din 1 deceniu

Answer 1

Răspuns:

Explicație pas cu pas:

din-inmultire

a)  1min=60s       1 ora = 60 min = 3600 s

$\displaystyle \frac{3}{10} \times 1minut =\frac{3}{10} \times 60^{(10} s = 3 \times 6=18 s$

$\displaystyle \frac{4}{5} \times 1 h= \frac{4}{5} \times 60^{(5} min = 4 \times 12 = 48 min \\sau =\frac{4}{5} \times 3600^{(5} s= 4 \times 720=2880 s$

b) 1 kg=1000g        1t=1000kg

$\displaystyle \frac{3}{4} \times 1kg=\frac{3}{4} \times 1000^{(4} g=3x250g=750g$

$\displaystyle \frac{9}{10} \times 1t= \frac{9}{10} \times 1000^{(10} kg=9\times 100=900kg$

c)1 metru =100 cm   1cm = 0,01 m

$\displaystyle \frac{3}{2} \times 1 m=\frac{3}{2} \times 100^{(2} cm=3 \times 50 cm = 150 cm$

$\displaystyle \frac{8}{5} \times 1 cm =\frac{8}{5} \times 0,01 m=\frac{8}{5} \times\frac{1}{100} m= \frac{8}{500}^{(8} m=0,016 m$

d)1secol=100ani      1deceniu=10ani

$\displaystyle \frac{3}{100} \times 1secol = \frac{3}{100} \times 100^{(100} ani=3 ani\\\frac{4}{10} \times 1 deceniu = \frac{4}{10} \times 10 ^{(10}ani =4 ani$