Question

Ma puteti ajuta vă rog?!

a)1+2+3+...+73
b)53+368:(1463:7-1608:8)

Answer 1

1)1+2+3+...+73=
[73x(73+1)]/2=
73x74/2=73x37=2.701
Suma Gauss=[n x(n+1)]/2
2)53+368:(209-201)
=53+368:8=53+46=99
1463:7=209
1608:8=201
368:8=46

Answer 2

$\text{La a) Folosim teorema lui gaus } \rightarrow~= \boxed{\dfrac {n(n+1)}{2}} \\ \\ 1+2+3+...+73 = \dfrac{73(73+1)}{2}=\dfrac{73\cdot74}{2} = \boxed{2701} \\ \\ \\ \\ \text{La b) facem niste calcule elementare, tinand cont de regula operatiilor.} \\ \\ 53+368:(1463:7-1608:8) = \\ 53+368:(209-201) = \\ 53+368:8 = \\ 53+46 = 99 \\ \\ Raspuns final \rightarrow \boxed{R:99}$