A=1+ (-2) + (-3) +4 +5 +(-6)+(-7)+8+...+99-100-101+102+103
a) A= 1+(-2)+(-3)+4+5(-6)+(-7)+8+9+...+99+100-101+102+103
b) B=1+(-3)+5+(-7)+...+57+(-99)+101
A=1+ (-2) + (-3) +4 +5 +(-6)+(-7)+8+...-99-100+101+102-103
Lời giải:\(A=(1-2)+(-3+4)+(5-6)+(-7+8)+....+(-99+100)+(101-102)-103\)
\(=-1+1+(-1)+1+....+1+(-1)+103=(-1)-103=-104\)
Tính:
a, A= 1+(-2)+(-3)+4+5+(-6)+(-7)+8+...+99-100-101+102+103
b,B=1+(-3)+5+(-7)+...+97+(-99)+101
1+(-2)+(-3)+4+5+(-6)+(-7)+8+.....+99-100-101+102+103
1 + ( -2 ) + (-3 ) + 4 + 5 + ( -6 ) + ..... + 99 - 100 - 101 + 102 + 103
[ 1 + ( -2 )] + [(-3 ) + 4] + [5 + ( -6 )] + ..... +[-98+ 99 ]- 100 - 101 + 102 + 103
= ( -1 ) + 1 + ( -1 ) + ..... + (-1 ) +....+ (-1 )- 100 -101 + 102 + 103
= 0 + 50 - 100 - 101 + 102 + 103
= 54
Mình không chắc
1+(-2)+(-3)+4+5+(-6)+(-7)+8+.....+99-100-101+102+103
= 1 + ( 2 - 3 - 4 + 5 ) + (6 - 7 - 8 + 9 ) + ... ( 98 - 99 -100 + 101 ) +102
= 1 + 0 + 0 + 0 + .... + 102
=103
Tính: 1-2-3+4+5-6-7+8-.....+99-100-101+102+103
B = 1 - 2 -3 + 4 + 5 - 6 - 7 + 8 +...+ 99 - 100 - 101 + 102 +103
B = 1-2-3+4+5-6-7+8+...+99-100-101+102+103
B = (1-2-3+4)+(5-6-7+8)+...+(99-100-101+102)+103
B = 0+0+...+0+103
B =103
Tính A
A = 1 + (-2) + (-3) + 4 + 5 + (-6) + (-7) + 8 + ... + 99 - 100 - 101 + 102 +103
\(A=1-2-3+4+5-6-7+8+...+99-100-101+102+103\\ =\left(1-2-3+4\right)+\left(5-6-7+8\right)+...+\left(99-100-101+102\right)+103\\ =0+..+0+103\\ =103\)
A = 1 + (-2) + (-3) + 4 + 5 + (-6) + (-7) + 8 + .......... + 99 - 100 - 101 + 102 + 103
A = 1 - 2 - 3 + 4 + 5 - 6 - 7 + 8 + ................ + 99 - 100 - 101 + 102 + 103
A = ( 1 - 2 - 3 + 4 ) + ( 5 - 6 - 7 + 8 ) + ............. + ( 99 - 100 - 101 + 102 ) + 103
A = 0 + 0 + ............. + 0 + 103
A = 0 + 103
A = 103
A=1+(-2)+(-3)+(-5)+(-6)+(-7)+8+...+99-100-101+102+103
tính :
A = 1 + (- 2) + (- 3) + 4 + 5 + (- 6) + (- 7) + 8 + . . . + 99 - 100 -101 + 102 + 103