( y+1) + ( y+2) + (y+3) + ( y+4)+...+( y+100) = 5750
=>( 100 x y )+ ( 1+2+3+4+ ...+ 100) = 5750
100 x y +[ (1+100) .100 : 2 ]= 5750
100 x y + 5050 = 5750
100 x y = 5750 - 5050
100 x y = 700
y = 700 : 100
y = 7
(y+1) +(y+2) + (y+3) + ( y+4) + ...+ (y+100)= 5750
............................
y=7
Hk tốt