Question

x=(1+2+3+___+98)+49​

Answer 1

Gauss:

1 + 2 + 3 + ... + n = n ( n + 1 ) : 2

x = ( 1 + 2 + 3 + ... + 98 ) + 49

x = [ 98 × ( 98 + 1 ) : 2 ] + 49

x = ( 98 × 99 : 2 ) + 49

x = ( 9 702 : 2 ) + 49

x = 4 851 + 49

x = 4 900

Answer 2

X=98×99:2+49

X=9702:2+49

X=4851+49

X=4900