Question

9. Calcule o valor numérico das expressões indicadas:
a) 7 - (4-6) - 15
b) - 5² - (-3)²
c) 2,4 x (-3) - 1,5 x 0,2
d) 1 - 1,92 + (-0,32)
e) 15. (- 2/3 )
f) - 2/5 x ( - 25/4 )
g) - 2/3 + 1 - 3/2
h) 2/3 (divido) 5/6 - 5
( As contas indicadas ex: 2/8 representão frações )
Eu preciso do calculo e a resposta :D

Answer 1

a)
$7 - (4 - 6) - 15 = 7 - ( - 2) - 15 = 7 + 2 - 15 = 5 - 15 = - 10$
b)
$- {5}^{2} - {( - 3)}^{2} = + 25 - 9 = 16$
c)
$2.4 \times ( - 3) - 1.5 \times 0.2 \\ \frac{24}{10} \times ( - 3) -15 \times \frac{2}{10} \\ \frac{12}{5} \times ( - 3) - 15 \times \frac{1}{5} \\ \frac{12}{5} \times \frac{ - 3}{1} - \frac{15}{1} \times \frac{1}{5} \\ \frac{ - 36}{5} - \frac{15}{5} \\ \frac{ - 21}{5}$
d)
$1 - 1.92 + ( - 0.32) \\ \frac{100}{100} - \frac{192}{100} + \frac{ - 032}{100} \\ \frac{ - 92}{100} + \frac{ - 32}{100} \\ \frac{ - 124}{100} = \frac{ - 31}{25}$
e)
$15( \frac{ - 2}{3}) \\ 15 \div 3( - 2) \\ 5( - 2) \\ - 10$
f)
$\frac{2}{5} \times \frac{ - 25}{4} \\ \frac{ - 50}{20} \\ \frac{ - 5}{2}$
g)
$\frac{ - 2}{3} + 1 - \frac{3}{2} \\ \frac{ - 4}{6} + \frac{6}{6} - \frac{9}{6} \\ \frac{ - 4 + 6 - 9}{6} \\ \frac{ - 7}{6}$
h)
$\frac{2}{3} \div \frac{5}{6} - 5 \\ \frac{2}{3} \times \frac{6}{5} - 5 \\ \frac{12}{15} - \frac{5}{1} \\ \frac{12}{15} - \frac{75}{15} \\ \frac{ - 63}{15} = \frac{21}{5}$