Question

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Answer 1

Răspuns:

$a) \frac{\frac{1}{4} }{5}=\frac{x}{6} \\\frac{1}{4} :5 =\frac{x}{6} \\\frac{1}{4} *\frac{1}{5} =\frac{x}{6\\}\\\frac{1}{20}=\frac{x}{6} \\20x=6\\x=6/20 =3/10$

$b) \frac{2,(3)}{x} =\frac{3,(2)}{\frac{1}{7} } \\\\\frac{2,(3)}{x} =3,(2) :\frac{1}{7} \\\frac{2,(3)}{x}=\frac{32-3}{9} *7\\\frac{2,(3)}{x} = \frac{29}{9}*7\\\frac{2,(3)}{x} =\frac{203}{9} \\2,(3)*9=203x\\\frac{23-2}{9}*9 =203x\\\frac{21}{9}*9 =203x\\203x=21\\ x=21/203$

$c) \frac{0,25}{0,5} =\frac{0,15}{x} \\0,25x=0,5*0,15\\\frac{25}{100}x =\frac{5}{10}*\frac{15}{100} \\\frac{25x}{100}=\frac{75}{1000} \\25x*1000=75*100\\25000x=7500\\x=7500/25000 =75/250= 3/10$

$d) \frac{3}{x+1} =\frac{4}{x+2} \\3(x+2)=4(x+1)\\3x+6=4x+4\\3x-4x=-6+4\\-x=-2\\x=2$$e) \frac{x^{2} }{8} =\frac{9}{2} \\2x^{2} =8*9\\2x^{2} =72\\x^{2} =36\\x^{2} =6^{2}\\x=6$

f) $\frac{\frac{1}{x} }{5} =\frac{3}{4} \\\frac{1}{x} :5=\frac{3}{4} \\\frac{1}{x} *\frac{1}{5}=\frac{3}{4}\\\frac{1}{5x}=\frac{3}{4} \\1*4=3*5x\\4=15x\\15x=4\\x=4/15$

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