( x + 100 ) + ( x + 99 ) + ( x + 98 ) + ........ + ( x + 2 ) + ( x + 1 ) = 5950
=> (x+x+x+.......+x)+(1+2+3+............+99+100)=5950
=> 100x+(100+1).100:2=5950
=> 100x+10100:2=5950
=>100x+5050=5950
=> 100x=5950-5050
=> 100x=900
=> x=900:100
=> x=9
( x + 100 ) + ( x + 99 ) + ( x + 98 ) + ........ + ( x + 2 ) + ( x + 1 ) = 5950
( x + x + x + ... + x + x ) + ( 100 + 99 + 98 + ... + 2 + 1 ) = 5950
100x + 5050 = 5950
100x = 5950 - 5050
100x = 900
x = 900 : 100
x = 9