Question

12 daca valoarea raportului x supra y este 1,5 calculati a y supra x, b 3×x supra 5×y ,c 2×x supra 3×y, d 2×y supra 3×x ,e x+y supra x-y ​

Answer 1

Explicație pas cu pas:

$\frac{x}{y} = 1.5 = \frac{15}{10} = > \frac{x}{y} = \frac{3}{2}$

a)

$\frac{y}{x} = \frac{2}{3}$

b)

$\frac{3x}{5y} = \frac{3}{5} \times \frac{x}{y} = \frac{3}{5} \times \frac{3}{2} = \frac{9}{10}$

c)

$\frac{2x}{3y} = \frac{2}{3} \times \frac{x}{y} = \frac{2}{3} \times \frac{3}{2} = 1$

d)

$\frac{2y}{3x} = \frac{2}{3} \times \frac{y}{x} = \frac{2}{3} \times \frac{2}{3} = \frac{4}{9}$

e)

$\frac{x + y}{x - y} = \frac{ \frac{x + y}{y} }{ \frac{x - y}{y} } = \frac{\frac{x}{y} + 1}{\frac{x}{y} - 1} = \frac{ \frac{3}{2} + 1}{ \frac{3}{2} - 1 } = \frac{3 + 2}{3 - 2} = \frac{5}{1} = 5$