Question

3. Scrieti sub forma cea mai simpla opusul numărului rational: a=|-2,1(3) |-|-1,(6)|
va rog e urgent !!!​

Answer 1

$a = | - 2.1(3)| - | - 1.(6)|$

$a = 2.1(3) - 1.(6)$

$a = 2 \frac{13 - 1}{90} - 1 \frac{6}{9}$

$a = 2\frac{12}{90} - 1 \frac{6}{9}$

$a = \frac{2 \times 90 + 12}{90} - \frac{1 \times 9 + 6}{9}$

$a = \frac{192}{90} - \frac{15}{9}$

$a = \frac{192}{90} - \frac{150}{90}$

$a = \frac{42}{90} = \frac{7}{15}$

$Opusul //lui //a //este - \frac{7}{15}$

Answer 2

$\it a=|-2,1(3)|-|1,(6)|=2,1(3)-1,(6)=2\dfrac{13-1}{90}-1\dfrac{6}{9}=\\ \\ \\ =\dfrac{192}{90}-\dfrac{^{10)}15}{\ 9}=\dfrac{192-150}{90}=\dfrac{\ 42^{(6}}{90}=\dfrac{7}{15}$

$\it\ \ Opusul \ \ lui\ \ a\ \ este\ \ -a=-\dfrac{7}{15}$