Toán 1+3-5-7+9+11-13-15+17+19-………….+401+403 13/07/2021 By Vivian 1+3-5-7+9+11-13-15+17+19-………….+401+403
1+3-5-7+9+11-13-15+17+19-………….+401+403 =(1+3-5-7) + (9+11-13-15)+…(393 + 395 – 397 – 399) + 401 + 403 = (-8) + (-8) + …+ (-8) + 401 + 403 (50 Số hạng -8) =(-8) x 50 + 401 + 403 = -400 + 401+ 403 = 1 + 403 = 404 Trả lời
1+3-5-7+9+11-13-15+17+19-………….+401+403
=1+(-2)+2+(-2)+…+2+403
=1+0+403
=404
1+3-5-7+9+11-13-15+17+19-………….+401+403
=(1+3-5-7) + (9+11-13-15)+…(393 + 395 – 397 – 399) + 401 + 403
= (-8) + (-8) + …+ (-8) + 401 + 403 (50 Số hạng -8)
=(-8) x 50 + 401 + 403
= -400 + 401+ 403
= 1 + 403
= 404