Question

heelpp, primele2 exerciții

Answer 1

$1) \\ \\ ( - \frac{1}{90}) : ( - \frac{1}{30}) - ( - \frac{3}{5}) ^{ - 1} = \\ \\ - \frac{1}{90} : - \frac{1}{30} - \frac{1}{ - \frac{3}{5} } = \\ \\ - \frac{1}{90} \times \frac{30}{ - 1} - \frac{1}{ - \frac{3}{5} } = \\ \\ - \frac{1 \times 30}{ - 90} - \frac{1}{ - \frac{3}{5} } = \\ \\ - \frac{30}{ - 90} - \frac{1}{ - \frac{3}{5} } = \\ \\ - ( - \frac{30}{90}) - \frac{1}{ - \frac{3}{5} } = \\ \\ - ( - \frac{1}{3}) - \frac{1}{ - \frac{3}{5} } = \\ \\ - ( - \frac{1}{3}) - ( - \frac{1}{ \frac{3}{5} }) = \\ \\ - ( - \frac{1}{3}) - ( - \frac{5}{3}) = \\ \\ \frac{1}{3} + \frac{5}{3} = \frac{6}{3} = 2$

Answer 2

(-1/90):(-1/30) - (-3/5)^(-1)=      (3/5)^(-1)=5/3            - cu - = +

⇒ 1/3 + 5/3 =6/3= 2              R-s:   ⇒D

-0,2=-1/5  ∈Q                Q- asta e Fractie a/b

0,2(5)=1/5+5/90 ∈Q

-√(2+ 1/4)= -√(9/4)=-3/2 ∈Q               R-s: B