Tìm x, biết: x + (x + 1) + x + 2) + ... + (x + 2010) = 2029099

1, Tìm x biết
a, x + ( x + 1) + ( x + 2) + ... + ( x + 2010) = 2029099
b, 2 + 4 + 6 + 8 + ... + 2. x = 210