Question

sume Gauss! ajutor! 4+8+12+......400

Answer 1

4+8+12+...+400=

4(1+2+3+...100)=

4×(100×101):2=

4×50×101=

200×101=

20200

Answer 2

dam factor comun pe 4
$4(1 + 2 + 3 + ... + 100)$
cunoastem formula generala pentru suma lui Gauss:
$s = \frac{n(n + 1)}{2}$
si o aplicam, in exercitiul de fata n=100
$4 \times \frac{100(100 + 1)}{2} = 4 \times \frac{100 \times 101}{2} = 4 \times (50 \times 101) = 4 \times 5050 = 20200$