Question

Mate! Exercițiul 36 punctul c va rog

Answer 1

Răspuns:

Explicație pas cu pas:

f(x) = 3 x + 6

f(1) = 3 × 1 + 6 = 3 + 6 = 9

f(2) = 3 × 2 + 6 = 6 + 6 = 12

f(3) = 3 × 3 + 6 = 9 + 6 = 15

............................................

f(35) = 3 × 35 + 6 = 105 + 6 = 111

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S = f(1) + f(2) + ......... + f(35)

S = 9 + 12 + 15 + ........ + 111

→ ( 111 - 9 ) : 3 + 1 = 102 : 3 + 1 = 34 + 1 = 35 termeni are suma cu ratia=3

→ aplic formula sumei lui Gauss

S = 35 × ( 9 + 111 ) : 2

S = 35 × 120 : 2

S = 2 100