Question

Daca 0,24•a/4,5 = 0,32/0,3 se cere a+12/12

Answer 1

24/100×a/45/10=32/100/3/10
24/100×a/45/10=32/100×10/3
24/100×a/45/10=320/300
24/100×a=320/300×45/10
24/100×a=96/20
a=24/100×20/96
a=1/(5×4)
a=1/20

a+12/12=1/20+1 amplificãm pe 1 cu 20
1/20+20/20=21/20

Answer 2

$0,24\cdot\dfrac{a}{4,5}=\dfrac{0,32}{0,3}$

0,24= $\dfrac{24}{100}$= $\dfrac{6}{25}$

$\dfrac{a}{4,5}$= $\dfrac{10a}{45}$= $\dfrac{2a}{9}$

0,32= $\dfrac{32}{100}$= $\dfrac{8}{25}$

0,3= $\dfrac{3}{10}$

$\dfrac{6}{25}$· $\dfrac{2a}{9}$= $\dfrac{\frac{8}{25}}{\frac{3}{10}}$

$\dfrac{2}{25}$· $\dfrac{2a}{3}$= $\dfrac{8}{25}$· $\dfrac{10}{3}$

$\dfrac{4a}{75}$= $\dfrac{80}{75}$

4a= $\dfrac{80\cdot 75}{75}$

4a=80

a= $\dfrac{80}{4}$=20

$\dfrac{a+12}{12}$= $\dfrac{20+12}{12}$= $\dfrac{32}{12}$= $\dfrac{8}{3}$