Question

(2+4+...+200)÷[( 4+8t...t 100)]: 13​

Answer 1

Răspuns:

Explicație pas cu pas:

2 + 4 + ... + 200 = 2*(1 + 2 + ... + 100) = 2*100*(1 + 100)/2 = 2*100*101/2 = 10100

4 + 8 + ... + 100 = 4*(1 + 2 + ...+ 25) = 4*25*(1 + 25)/2 = 4*25*26/2 = 100*13 = 1300

(2+4+...+200)÷[( 4+8t...t 100): 13]​ = 10100 : (1300 : 13) = 10100 : 100 = 101