a/ Đặt x+1= 2017
Ta có A = x6 - (x + 1)x5 + (x+1)x4 - (x +1)x3 + (x+1)x2 - (x +1)x + (x+1)
A= x6 - x6 - x5 + x5 +x4 - x4 -x3 + x3 + x2 - x2 -x +x +1
A= 1
k cho mình nha
B= x10 - (x+1)x9 + (x+1)x8 - (x+1)x7 + ..... +( x+1)x2 - (x+1)x
B= x10 - x10 - x9 + x9 + x8 - x8 - x7 + x7 +..... + x3 + x2 - x2 - x
B= -x
=> B= -2015
k cho mình