2 - 4 + 6 - 8 + 10 - 12 + 14 - 16 + 18
= -2 + -2 + -2 + -2 + 18
= -8 + 18
= 10
2 - 4 + 6 - 8 + 10 - 12 + 14 - 16 + 18
=10
hok tốt
\(2-4+6-8+10-12+14-16+18
\)
\(=2+6+10+14+18-\left(4+8+12+16\right)\)
\(=2+18+6+14+10-\left(4+16+8+12\right)\)
\(=20+20+10-\left(20+20\right)\)
\(=50-40\)
\(=10\)
2 - 4+6-8+10-12+14-16+18
= (2-4)+(6-8)+(10-12)+(14-16)+18
= -2 + (-2)+(-2)+(-2) + 18
= 10