Question

stabileste daca urmatoarele numere sunt patrate perfecte: 1+3+5+...+49
PLS E PE MÂINE VA ROG RAPID!!!!!

Answer 1

(1+49) x 25 : 2 = 50 x 25 : 2 = 25 x 25 = 25^2

Answer 2

1+3+5+...+49 =
Aflam cati termeni are suma:
(49 - 1) : 2 + 1 = 48:2 + 1 = 25
= (49 + 1) × 25 : 2 =
= 50 × 25 : 2 =
= 25 × 25 =
= 25^2 p.p

sau
1+3+5+...+49 =
= 2×0+1 + 2×1+1 + 2×2+1+...+×2×24+1 =
= 2×(0+1+2+...+24) + 1+1+...+1 de 25 ori =
= 2 × 24 × (24+1) : 2 + 1×25 =
= 24 × 25 + 25 =
= 25×(24+1) =
= 25 × 25 =
= 25^2