Question

Știind că
$\frac{x}{y} = \frac{7}{9} \\ d) 18x - 14y + 25$
Tot supra :
$12 + 9x - 7y$
e) 4 + 27x - 21y
------------------
9x +5 - 7y

f). 2,5+4,5x-3,5y
-------------------
0,9x + 1 - 0,7y​

Answer 1

Răspuns:

$\frac{x}{y} =\frac{7}{9}$⇒ 7y=9x

d) $\frac{18x-14y+25}{12+9x-7y} =\frac{18x-18x+25}{12+9x-9x}=\frac{25}{12}$

e) $\frac{4+27x-21y}{9x+5-7y}=\frac{4+21y-21y}{7y+5-7y}=\frac{4}{5}$

f)$\frac{2,5+4,5x-3,5y}{0,9x+1-0,7y}=\frac{2,5+4,5x-4,5x}{0,7y+1-0,7y}  = 2,5$

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