Question

16,17,18 va rog:)) la mate dau coroana❤️

Answer 1

Exercitiul 16:

l-7l = 7

l12l = 12

l4l = 4

l-2l = 2

l-25l = 25

l17l = 17

l0l = 0

l-10l = 10

l-15l = 15

Exercitiul 17:

a) l-10l > -10

   10 > -10 (adevarat)

b) l2l = 2

    2 = 2 (adevarat)

c) l-3l = -3

    3 = -3 (fals)

d) l-4l < 2

    4 < 2 (fals)

e) l2l = 1

     2 = 1 (fals)

Exercitiul 18:

a) l-1l + l-2l + l-3l + ..... + l-10l = 1 + 2 + 3 + ..... + 10 = (10 + 1) x 10 : 2

= 11 x 5 = 55

b) l-1l + l2l + l-3l + ..... + l10l = 1 + 2 + 3 + .... + 10 = 55

c) l-9l + l-7l + l-5l + l-3l + l-1l + l1l + l3l + l5l + l7l + l9l = 9 + 7 + 5 + 3 + 1 + 1 + 3 + 5 + 7 + 9 = 2 x 9 + 2 x 7 + 2 x 5 + 2 x 3 + 2 x 1 = 2(1 + 3 + 5 + 7 + 9) = 2 x 25 = 50