Question

Calcule o valor da expressão A) -7/6+ 5/4 b) -2/5×0,7 c)4×9/4 d) 3,5 - 11/3

Answer 1

Explicação passo-a-passo:

a)

$\sf -\dfrac{7}{6}+\dfrac{5}{4}$

$\sf mmc(4,6)=12$

$\sf -\dfrac{7}{6}+\dfrac{5}{4}$

$\sf =\dfrac{2\cdot(-7)+3\cdot5}{12}$

$\sf =\dfrac{-14+15}{12}$

$\sf =\dfrac{1}{12}$

b)

$\sf -\dfrac{2}{5}+0,7$

$\sf =-0,4+0,7$

$\sf =0,3$

c)

$\sf -4+\dfrac{9}{4}$

$\sf =\dfrac{4\cdot(-4)+1\cdot9}{4}$

$\sf =\dfrac{-16+9}{4}$

$\sf =-\dfrac{7}{4}$

d)

$\sf 3,5-\dfrac{11}{3}$

$\sf =\dfrac{7}{2}-\dfrac{11}{3}$

$\sf mmc(2,3)=6$

$\sf \dfrac{7}{2}-\dfrac{11}{3}$

$\sf =\dfrac{3\cdot7-2\cdot11}{6}$

$\sf =\dfrac{21-22}{6}$

$\sf =-\dfrac{1}{6}$

Answer 2

$\\tt{a)} ~\sf{-\dfrac{7}{6}+\dfrac{5}{4}=\dfrac{-14+15}{12}=\dfrac{1}{12}}\\\tt{b)}~\sf{-\dfrac{2}{5}+0,7=-0,4+0,7=0,3}\\\tt{c)}~\sf{-4+\dfrac{9}{4}=\dfrac{-16+9}{4}=-\dfrac{7}{4}}\\\tt{d)}~\sf{3,5-\dfrac{11}{3}=\dfrac{7}{10}-\dfrac{11}{3}}\\\sf{\dfrac{21-110}{30}=-\dfrac{89}{30}}$