Question

care dintre numere este mai mare?
A=1+3+5+...+399
B=(1+2+...+560):4​

Answer 1

Răspuns:

$s \: = \frac{x \times x + 1}{2}$

$a = \frac{399 \times 399 + 1}{2} = \frac{159.600}{2} = 79.800$

$b = ( \frac{560 \times 560 + 1}{2} ) \div 4 =( \frac{314.160}{2} ) \div 4 = 157.080 \div 4 = 39.270$

79.800 > 39.270 => A > B