Question

Aflati termenul necunoscut al proportiei.Dau coroană!​

Answer 1

Salut!

Cerinta: Aflati termenul necunoscut al proportiei.

Raspuns:

a) $\frac{2\frac{1}{3} }{0.5} = \frac{x}{3}$

$3(\frac{2\frac{1}{3} }{0.5} ) = x$

$\frac{6\frac{3}{3} }{0.5}$

$\frac{6+\frac{3}{3} }{0.5}$

$\frac{7}{0.5}$

$14 = x$

$x = 14$

b) $\frac{14.3}{x-2} = \frac{10}{2.5}$

$\frac{14.3}{x-2} = 4$

$(x-2)(\frac{14.3}{x-2} ) = 4(x-2)$

$14.3 = 4(x-2)$

$a(b+c) = ab + ac$

$14.3 = 4x - 8$

$14.3 + 8 = 4x - 8 + 8$

$22.3 = 4x$

$\frac{22.3}{4} = \frac{4x}{4}$

$5.575 = x$

$x = 5.575$

c) $\frac{x+1}{18\frac{4}{5} } = \frac{1\frac{3}{10} }{7.2}$

$7,2 = 7+ 0.2 = 7+\frac{1}{5} = 7\frac{1}{5}$

$\frac{x+1}{18\frac{4}{5} } = \frac{1\frac{3}{10} }{7\frac{1}{5} }$

$18\frac{4}{5} (\frac{x+1}{18\frac{4}{5} } = 18\frac{4}{5} (\frac{1\frac{1}{10} }{7\frac{1}{5} })$

$x +1 = \frac{\frac{90}{5} +\frac{4}{5}(\frac{10}{10} +\frac{3}{10} ) }{\frac{35}{5}+\frac{1}{5} }$

$x +1 = \frac{\frac{94}{5}(\frac{13}{10} ) }{\frac{36}{5} }$

$x+1= \frac{\frac{1222}{50} }{\frac{36}{5} }$

$x+1 = \frac{6110}{1800}$

$x + 1 =\frac{611}{180}$

$x + 1 - 1 = \frac{611}{180} -1$

$x=\frac{611}{180} - \frac{180}{180}$

$x=\frac{611-180}{180}$

$x=\frac{431}{180}$

$x = \frac{360}{180} + \frac{71}{180}$

$x = 2+\frac{71}{180}$

$x = 2\frac{71}{180}$ ≈ $2.394$

d) $\frac{14}{25\frac{1}{5} } = \frac{15}{2x-1}$

$2x-1(\frac{14}{25\frac{1}{5} } = \frac{15}{2x-1} (2x-1)$

$(2x-1)(\frac{14}{25\frac{1}{5} } )=15$

$(2x-1)(25\frac{1}{5} )(\frac{14}{25\frac{1}{5} } )=15(25\frac{1}{5})$

$(2x-1)(14)=375+\frac{15}{5}$

$(2x-1)(14)=375+3$

$(2x-1)(14)=378$

$\frac{(2x-1)(14)}{14} = \frac{378}{14}$

$2x-1=27$

$2x-1+1=27+1$

$2x=28$

$\frac{2x}{2} = \frac{28}{2}$

$x = 14$

Sper ca te-am ajutat!