Question

Preciso das contas por favor me ajudem fazenda as contas .

Answer 1

Resposta:

Explicação passo a passo:

a)

$\frac{x}{3} =7\\\\\frac{x}{3} =\frac{7}{1} \\\\x=7.3\\\\\\\x=21$

b)

$\frac{x}{4} =-3\\\\\frac{x}{4} =-\frac{3}{1} \\\\x=-12$

c)

$\frac{2x}{5} =4\\\\\frac{2x}{5} =\frac{4}{1} \\\\2x=4.5\\\\2x=20\\\\x=\frac{20}{2} \\\\x=10$

d)

$\frac{2x}{3} =10\\\\\frac{2x}{3} =\frac{10}{1} \\\\2x=3.10\\2x=30\\\\x=\frac{30}{2} \\\\x=15$Para ser -15 teria que um dos números ter o sinal de menos (-).

e)

$\frac{3x}{4} =30\\\\\frac{3x}{4} =\frac{30}{1} \\\\3x=4.30\\\\3x=120\\\\x=\frac{120}{3} \\\\\\x=40$

f)

$\frac{2x}{5} =-18\\\\\frac{2x}{5} =-\frac{18}{1\\} \\\\2x=5.(-18)\\\\2x=-90\\\\x=-\frac{90}{2} \\\\x=-45$