Explicație pas cu pas:
1.
[tex]6 - 3 + 5 - 4 + 6 = 17 - 7 = 10[/tex]
R: 10 etaje
2.a)
[tex]( + 17) - ( + 2) = 17 - 2 = 15 \\ ( + 2) - ( + 32) = 2 - 32 = - 30[/tex]
b)
[tex]( - 3) - ( - 18) = - 3 + 18 = 15 \\ ( - 34) - ( - 4) = - 34 + 4 = - 30[/tex]
c)
[tex]( + 11) - ( - 4) = 11 + 4 = 15 \\ ( - 23) - ( + 7) = - 23 - 7 = - 30[/tex]
3. 9999
a) 9999 - (-98) = 9999 + 98 = 10097
b) 9999 - (-999) = 9999 + 999 = 10998
c) 9999 - (-9876) = 9999 + 9876 = 19875
4. |x| < 90 => -90 < x < 90 => x = 89
y = 9² = 81
[tex]x - y = ( - 89) - ( + 81) = - (89 + 81) = - 170 \\ [/tex]
5.a)
[tex]1 \times 5 = 5 \\ ( - 1) \times ( - 5) = 5[/tex]
b)
[tex]1 \times 9 = 9 \\ ( - 1) \times ( - 9) = 9 \\ 3 \times 3 = 9 \\ ( - 3) \times ( - 3) = 9[/tex]
c)
[tex]( - 1) \times 7 = - 7 \\ 1 \times ( - 7) = - 7[/tex]
d)
[tex]( - 1) \times 10 = - 10 \\ 1 \times ( - 10) = 10 \\ ( - 2) \times 5 = - 10 \\ 2 \times ( - 5) = - 10[/tex]
