Question

va rog sa ma ajutati la cele incercuite dau coroana ❤

Answer 1

14.
a)
$\frac{10}{x} = \frac{1}{9}$
amplific a doua fractie cu 10
=>
$\frac{10}{x} = \frac{10}{90}$
=>x=90
b)
$\frac{x}{2} = \frac{3}{5}$
amplific prima fractie cu 5 si pe a doua cu 2
=>
$\frac{5x}{10} = \frac{6}{10}$
=>5x=6
$x = \frac{6}{5}$
c)
$\frac{x}{1} = \frac{0}{6}$
amplific prima fractie cu 6
=>
$\frac{6x}{6} = \frac{0}{6}$
=> 6x=0
x=0
d)
$\frac{0.2}{x} = \frac{1.75}{2} \\ \frac{ \frac{2}{10} }{x} = \frac{ \frac{175}{100} }{2} \\ \frac{1}{5} \times \frac{1}{x} = \frac{33}{20} \times \frac{1}{2} \\ \frac{1}{5x} = \frac{33}{40} \\ amplific \: prima \: fractie \: cu \: 33 \\ \frac{33}{5x} = \frac{33}{40} \\ 5x = 40 \\ x = 8$
e)
$\frac{1.82}{6.3} = \frac{x}{8} \\ \frac{ \frac{182}{100} }{ \frac{63}{10} } = \frac{x}{8} \\ \frac{91}{50} \times \frac{10}{63} = \frac{x}{8} \\ \frac{91}{315} = \frac{x}{8} \\ 315 \times x = 91 \times 8 \\ 315 \times x = 728 \\ x = \frac{728}{315}$
f)
$\frac{1.(3)}{x} = \frac{1}{9} \\ \frac{ \frac{13 - 1}{9} }{x} = \frac{1}{9} \\ \frac{12}{9} \times \frac{1}{x} = \frac{1}{9} \\ \frac{12}{9x} = \frac{1}{9} \\ amplific \: a \: doua \: fractie \: cu \: x \\ \frac{12}{9x} = \frac{x}{9x} \\ = > x = 12$
g)
$\frac{1.2}{x} = \frac{72}{2} \\ \frac{ \frac{12}{10} }{x} = \frac{72}{2} \\ \frac{6}{5} \times \frac{1}{x} = \frac{72}{2} \\ \frac{6}{5x} = \frac{72}{2} \\ amplific \: prima \: fractie \: cu \: 12 \\ \frac{72}{60x} = \frac{72}{2} = > 60x = 2 \\ x = \frac{1}{30}$
h)
$\frac{x}{2} = \frac{3.(4)}{5} \\ \frac{x}{2} = \frac{ \frac{34 - 3}{9} }{5} \\ \frac{x}{2} = \frac{31}{9} \times \frac{1}{5} \\ \frac{x}{2} = \frac{31}{45} \\ amplfic \: prima \: fractie \: cu \: 45 \: si \: pe \: a \: doua \: cu \: 2 \\ = > \\ \frac{45x}{90} = \frac{62}{90} \\ 45x = 62 \\ = > x = \frac{62}{45}$