x + 2 + x + 4 + x + 6 + ..... + x + 100 = 2700
50x + 2 + 4 + 6 + ..... + 100 = 2700
50x + (100 + 2) x 50 : 2 = 2700
50x + 2550 = 2700
50x = 2700 - 2550 = 150
x = 150 : 50 = 3
x + 2 + x + 4 + x + 6 + ... + x + 100 = 2700
50x + 2 + 4 + 6 + .... + 100 = 2700
50x + ( 100 + 2 ) x 50 : 2 = 2700
50x + 2550 = 2700
50x = 2700 - 2550 = 150
x = 150 : 50 = 3
=> ( x + x + x + .... x + x ) + ( 2 + 4 + 6 + .... + 100 ) = 2700
=> 50x + 2.( 1 + 2 + 3 + .... + 50 ) = 2700
=> 50x + 2.{ [ 50.( 50 + 1 ) ] : 2 } = 2700
=> 50x + 2.1275 = 2700
=> 50x + 2550 = 2700
=> 50x = 2700 - 2550
=> 50x = 150
=> x = 150 : 50
=> x = 3