Question

Calculati :

a) 27-25+23-21+...+7-5+3-1
b) 28-26+24-22+...+8-6+4-2​

Answer 1

Răspuns:

Explicație pas cu pas:

a) 27-25+23-21+...+7-5+3-1 = ?

27-25+23-21+...+7-5+3-1 =

= 2+2+2+2+2+2+2 = 2x7 = 14

Numarul de termeni = (27-1):2 + 1 = 14 =>

7 perechi de numere (7 de 2)

b) 28-26+24-22+...+8-6+4-2​ = ?

28-26+24-22+...+8-6+4-2​ =

= 2+2+2+2+2+2+2= 14

Numarul de termeni = (28-2):2 +1 = 14 =>

7 perechi de numere (7 de 2)