Question

3-Determine as seguintes somas:
a) (-4/5)+(+1/2)
b) (+5/6)+(-2/1)
c) (-025) + (-0,75)=
d) (+0,2)+(-1/4)
e) (12/30)+(-0,04)​
porfavor e pra amanhã​

Answer 1

Explicação passo-a-passo:

a)

$\sf \Big(-\dfrac{4}{5}\Big)+\Big(+\dfrac{1}{2}\Big)$

$\sf =-\dfrac{4}{5}+\dfrac{1}{2}$

• $\sf mmc(2,5)=10$

$\sf -\dfrac{4}{5}+\dfrac{1}{2}$

$\sf =\dfrac{-4\cdot2+1\cdot5}{10}$

$\sf =\dfrac{-8+5}{10}$

$\sf =\red{\dfrac{-3}{10}}$

b)

$\sf \Big(+\dfrac{5}{6}\Big)+\Big(-\dfrac{2}{1}\Big)$

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

• $\sf mmc(1,6)=6$

$\sf \dfrac{5}{6}-\dfrac{2}{1}$

$\sf =\dfrac{5\cdot1-2\cdot6}{6}$

$\sf =\dfrac{5-12}{6}$

$\sf =\red{\dfrac{-7}{6}}$

c)

$\sf (-0,25)+(-0,75)$

$\sf =-0,25-0,75$

$\sf =\red{-1}$

d)

$\sf (+0,2)+\Big(-\dfrac{1}{4}\Big)$

$\sf =0,2-\dfrac{1}{4}$

$\sf =0,2-0,25$

$\sf =\red{-0,05}$

e)

$\sf \Big(\dfrac{12}{30}\Big)+(-0,04)$

$\sf =\dfrac{12}{30}-0,04$

$\sf =0,4-0,04$

$\sf =\red{+0,36}$