Question

Va rog sa rezolvati urmatorul exercitiu cu suma lui Gauss:

2+4+6+.....+102=?

5+10+15+...+250=?

1+4+7+...+235=?



URGENT!!! DAU COROANA​

Answer 1

Răspuns:

S=2+4+6+.....+102

S=2( 1+2+3+..+51)

S= 2×\frac{51*52}{2}

2

51∗52

S=2×\frac{2652}{2}

2

2652

S=2×1326

S=2652

5(1+2+34+...50+)=5X50/2=6375

Answer 2

Răspuns:

2+4+6+....+102=(102+2) x [(102-2):2+1]:2=52 x 51 = 2652

5+10+15+...+250=(250+5) x [(250-5):5+1]:2 = 255x25=6375

1+4+7+...+235=(235+1)x{(235-1):3+1]:2=119x79=9401