Question

calculati a)(1+2+3+.......+14 ) ÷(1+2+3+.....+6)
B)(1×2×3×....×15)÷(1+2+3+...+15)​

Answer 1

Răspuns:

Explicație pas cu pas:

a)

(1+2+3+.......+14 ) ÷(1+2+3+.....+6) =

[14 x (14+1) : 2] : [6 x (6+1):2] =

[7 x 15] : [ 3x 7] =

105 : 21 =

5

b)

(1×2×3×....×15)÷(1+2+3+...+15)​

[1×2×3×....×15] : [15 x (15+1):2] =

[1×2×3×....×15] : [15 x 16 : 2] =

[1×2×3×....×15] : [15 x 8 ]=

[1×2×3×.4 x 5 x...×15] : [1 x 2 x 3 x 4 x 5] =

6 x 7 x 8 x 9 .....x 15

sau = 10897286400