Question

5)Determine x em cada um a das seguintes
proporções​

Answer 1

Olá!

A)

$\frac{7}{3}=\frac{x}{12}\\\\\frac{x}{12}=\frac{7}{3}\\\\\frac{x}{12}=\frac{7}{3}\\\\\frac{12x}{12}=\frac{7\cdot \:12}{3}\\\\x=28$

B)

$\frac{2x}{15}=\frac{6}{9}\\\\\frac{2x}{15}=\frac{2}{3}\\\\\frac{15\cdot \:2x}{15}=\frac{2\cdot \:15}{3}\\\\2x=10\\\\\frac{2x}{2}=\frac{10}{2}\\\\x=5$

C)

$\frac{6}{3}=\frac{x}{0.5}\\\\\frac{x}{0.5}=\frac{6}{3}\\\\\frac{x}{0.5}=2\\\\\frac{0.5x}{0.5}=2\cdot \:0.5\\\\x=1$

D)

$\frac{x+1}{5}=\frac{x}{3}\\\\\left(x+1\right)\cdot \:3=5x\\\\3x+3=5x\\\\3x+3-3=5x-3\\\\3x=5x-3\\\\3x-5x=5x-3-5x\\\\-2x=-3\\\\\frac{-2x}{-2}=\frac{-3}{-2}\\\\x=\frac{3}{2}$

Espero ter ajudado, tenha bons estudos!