2. a) vei avea
[tex] (- x )\times( - y)[/tex]
ai "-" cu "-", deci devine plus
[tex]( - x) \times ( - y) = x \times y[/tex]
b) vei avea
[tex]( - x) \times y[/tex]
ai "-" cu "+", deci devine minus
[tex]( - x) \times y = - (x \times y)[/tex]
1. b)
[tex]2 \div ( - 1) - ( - 3 + ( - 5 - 1) \div ( - 2))[/tex]
[tex]2 \div ( - 1) = \frac{2}{ - 1} = - \frac{2}{1} = - 2[/tex]
paranteza 2:
[tex] - 5 - 1 = - 6[/tex]
[tex] \frac{ - 6}{ - 2} = \frac{6}{2} = 3[/tex]
[tex] - 3 + 3 = 0[/tex]
= -2 * 0
= 0
