Question

Dacă $\frac{2x+5y}{x+y}$ = 4,5 ,află :

a) $\frac{x}{y}$ = .................
b) $\frac{5x}{2y}$ = ....................
c) $\frac{x ^{2}+ y^{2} }{ y^2}}$ = ..............

Answer 1

$\frac{2x+5y}{x+y} =4,5$

$\frac{2x+5y}{x+y} = \frac{45}{10}$

10*(2x+5y)=45*(x+y)
20x+50y=45x+45y
25x=5y
5x=y

a)x/y=1/5
b)5x/2y=5/2*1/5=1/2
c)$\frac{ x^{2}+y^2}{y^2} = \frac{x^2}{y^2} + \frac{y^2}{y^2} =( \frac{x}{y} )^2+1= \frac{1}{25} +1= \frac{26}{25}$