Question

Calcule valor das expressoes abaixo:

Answer 1

a) $\sf \left(\dfrac{5}{2}-3\right)+\left(1~\dfrac{1}{2}-\dfrac{2}{3}\right)=\dfrac{5-6}{2}+\left(\dfrac{3}{2}-\dfrac{2}{3}\right)$

$\sf =\dfrac{-1}{2}+\left(\dfrac{9-4}{6}\right)=\dfrac{-1}{2}+\dfrac{5}{6}$

$\sf =\dfrac{-3+5}{6}=\dfrac{2}{6}=\dfrac{1}{3}$

b) $\sf \left(-\dfrac{5}{7}\right)^0-(-1)^7-2=1-(-1)-2$

$\sf =1+1-2=0$

c) $\sf \left(+\dfrac{2}{3}\right)^{-2}+3\cdot\left(-\dfrac{1}{2}\right)^3=\dfrac{9}{4}+3\cdot\left(-\dfrac{1}{8}\right)$

$\sf =\dfrac{9}{4}-\dfrac{3}{8}=\dfrac{18-3}{8}=\dfrac{15}{8}$

d) $\sf \sqrt{\dfrac{25}{16}}+\sqrt{0,0225}-\sqrt{0,16}=\dfrac{5}{4}+\dfrac{3}{20}-\dfrac{2}{5}$

$\sf =\dfrac{25+3-8}{20}=\dfrac{20}{20}=1$

a) $\sf (-1-1)\cdot\left(\dfrac{5}{4}-2\right)-\dfrac{1}{2}=(-2)\cdot\left(\dfrac{5-8}{4}\right)-\dfrac{1}{2}$

$\sf =(-2)\cdot\left(-\dfrac{3}{4}\right)-\dfrac{1}{2}=\dfrac{3}{2}-\dfrac{1}{2}$

$=\dfrac{3-1}{2}=\dfrac{2}{2}=1$

b) $\sqrt{0,09}-3\cdot0,2\cdot(-0,1)^2-\sqrt{0,04}=0,3-0,6\cdot0,01-0,2$

$\sf =0,3-0,06-0,2=0,04$