Question

sendo x= (2/7) : ( -4/7) e y= 1/x calcule as seguintes expressões.
a) x + y

b) x - y

c) x • y

d) x : y​

Answer 1

Explicação passo-a-passo:

$x = ( \frac{2}{7} ) \div ( - \frac{4}{7} )$

$x = \frac{2}{7} \times - \frac{7}{4} =$

$x = - \frac{14( \div 7)}{28( \div 7)} =$

$x = - \frac{2( \div 2)}{4( \div 2)} = - \frac{1}{2}$

$y = \frac{1}{x}$

$y = 1 \div - \frac{1}{2}$

$y = 1 \times - \frac{2}{1}$

$y = - 2$

a) x + y =

-1/2 + ( - 2 ) =

-1/2 - 2 =

-1 - 4/2 =

-5/2 = - 2,5

b) x - y =

-1/2 - (-2)=

-1/2 + 2 =

-1 + 4/2=

3/2 = 1,5

c) x • y =

-1/2 × - 2 =

2/2 = 1

d) x : y =

-1/2 : - 2 =

-1/2 × -1/2 =

1/4 = 0,25