Question

2) Encontre o valor de x nas proporções:
a) 5/4 = 20/x
b) 7/x = 2/20
c) x/3 = 100/10

Answer 1

a) $\frac{5}{4}=\frac{20}{x}$

$5x=20\cdot 4$

$5x=80$

$x=\frac{80}{5}$

$x=16$

b) $\frac{7}{x}=\frac{2}{20}$

$\frac{7}{x}=\frac{1}{10}$

$7\cdot 10=x$

$70=x$

$x=70$

c) $\frac{x}{3}=\frac{100}{10}$

$\frac{x}{3}=10$

$x=3\cdot 10$

$x=30$