Question

Calcule os termos conhecidos:
6/8 e 60/×=
4/× e 5/40=
5/× e 20/×-3=
3/4 e 60/×=
6/10 e 12/×=

Answer 1

$\frac{6}{8} = \frac{60}{x} \\ 6x = 480 \\x = \frac{480}{6} = 80$

$\frac{4}{x} = \frac{5}{40} \\5x = 160 \\ x = \frac{160}{5} = 32$

$\frac{5}{x} = \frac{20}{x - 3} \\ 5x - 15 = 20x \\ 20x - 5x = - 15$

$15x = - 15 \\ x = - \dfrac{15}{15} = - 1$

$\frac{3}{4} = \frac{60}{x} \\ 3x = 240 \\x = \dfrac{240}{3} = 80$

$\frac{6}{10} = \frac{12}{x} \\ 6x = 120 \\ x = \frac{120}{6} = 20$