Question

Ajudem a questão 4,5,10 e 12

Answer 1

4)

a)

$\sqrt[3]{343} = \sqrt[3]{ {7}^{3} } = 7$

b)

$\sqrt[3]{64} = \sqrt[3]{ {2}^{6} } = {2}^{ \frac{6}{3} } = {2}^{2} = 4$

c)

$\sqrt[3]{125} = \sqrt[3]{ {5}^{3} } = 5$

d)

$\sqrt[3]{512} = \sqrt[3]{ {2}^{9} } = {2}^{ \frac{9}{3} } = {2}^{3} = 8$

e)

$\sqrt[3]{729} = \sqrt[3]{ {3}^{6} } = {3}^{ \frac{6}{3} } = 3 {}^{2} = 9$

f)

$\sqrt[3]{1000} = \sqrt[3]{ {10}^{3} } = 10$

g)

$\sqrt[3]{216} = \sqrt[3]{ {3}^{3} \times {2}^{3} } = 3 \times 2 = 6$

5)

a)

$t + 14 = \frac{t}{2} - 18 \\ \\ 2(t + 14) = 2( \frac{t}{2} - 18) \\ \\ 2t + 28 = t - 36 \\ \\ 2t - t = - 36 - 28 \\ \\ t = - 64$

b)

$2h - 15 = 20 \\ \\ 2h = 20 + 15 \\ \\ 2h = 35 \\ \\ h = \frac{35}{2} \\ \\ h = 17.5$

c)

$30 - 5g = g + 25 \\ \\ - 5g - g = 25 - 30 \\ \\ - 6g = - 5 \\ \\ g = \frac{ - 5}{ - 6} \\ \\ g = \frac{5}{6}$

d)

$3y - 20 = 27 - 18 \\ \\ 3y = 27 - 18 + 20 \\ \\ 3y = 29 \\ \\ y = \frac{29}{3}$

10)

Escala 1cm representa 40000cm reais.

$\frac{1cm}{40000cm} = \frac{38 \times 10 {}^{ - 1}cm }{r} \\ \\ \\ 1cmr = (4 \times 10 {}^{4} cm) \times (38 \times 10 {}^{ - 1} cm) \\ \\ 1cmr = 152 \times 10 {}^{3} cm {}^{2} \\ \\ 1cmr = 152000cm {}^{2} \\ \\ \frac{1cmr}{1cm} = \frac{152000cm {}^{2} }{1cm} \\ \\ r = 152000cm$

r=1520000mm=152000cm=15200dm=1520m=152dam=15,2hm=1,52km

12)

$\frac{35}{100} \times \frac{840}{1} = \frac{29400}{100} = 294$