Question

CALCULE OS VALORES INDICADOS.

Answer 1

Resposta:

Explicação passo a passo:

$a)\frac{15}{5} =\frac{20}{x} \\\\15.x=20.5\\\\x=\frac{20.5}{15} \\\\x=\frac{20}{3}\\\\\\b)\frac{4}{12} =\frac{x}{21} \\\\12.x=21.4\\\\x=\frac{21.4}{12} \\\\x=7\\\\\\c)\frac{32}{8} =\frac{y}{6} \\\\y.8=32.6\\\\y=\frac{32.6}{8} \\\\y=24\\\\d)\frac{8}{x+1}=\frac{12}{2x-6} \\\\\frac{8}{x+1}=\frac{6}{x-3}\\\\8\left(x-3\right)=\left(x+1\right)\cdot \:6\\\\8x=6x+30\\\\2x=30\\\\x=\frac{30}{2} \\\\x=15$

$e)\frac{2x-2}{3x+1} =\frac{4}{7} \\\\\left(2x-2\right)\cdot \:7=\left(3x+1\right)\cdot \:4\\\\14x-14=12x+4\\14x-12x=14+4\\\\2x=18\\\\x=\frac{18}{2} \\x=9$