Tính nhanh: 50 – 18 + 16 + 14 – 12 – 10
tính nhanh:
2-4+6-8+10-12+14-16+18-20+22
10+12+14+16+...+80
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
60-61+50-51+40-41+30-31+20-21+10-11+70
2-4+6-8+10-12+14-16+18-20+22
=(2+18)-(4+16)+(6+14)-(8+12)-(10+20)+22
=20-20+20-20-20+22
=22-20
=2
1999-2000+2999-3000+3999-4000+4999-5000+5999-1000
=(1999-1000)+(2999-2000)+(3999-3000)+(4999-4000)+(5999-5000)
=999x5
=4995
2-4+6-8+10-12+14-16+18-20+22 =2+(6-4)+(10-8)+(14-12)+(18-16)+(22-20) = 2+2+2+2+2+2 = 12
Tính nhanh:
12 - 13 + 14 - 15 + 16
18 - 16 + 14 - 12 + 10 - 8
12 - 13 + 14 - 15 + 16
= -1+ (-1) + 16
= 0 + 16 = 16
18 - 16 + 14 - 12 + 10 - 8
= 2 + 2 + 2 = 6
12-13+14-15+16=(-1)+(-1)+16=(-2)+16=14
18-16+14-12+10-8=2+2+2=6
12 - 13 + 14 - 15 + 16 = 14
18 - 16 + 14 - 12 + 10 - 8 = 6
tính nhanh
10+12+14+16+18+20
10+12+14+16+18+20
=(10 + 20 ) + (14 + 16 ) + ( 12 + 18 )
= 30 + 30 + 30
= 90
k nha
Tính nhanh
1/2*4+1/4*6+1/6*8+1/8*10+1/10*12+1/10*14+1/14*16+1/16*18+1/18*20
20-18+16-14+12-10+8-6+4-2 tính nhanh
= (20 - 18 ) + (16 - 14 ) + ( 12 - 10 ) + ( 8 - 6 ) + ( 4 - 2 )
= 2 + 2 + 2 + 2 + 2
= 2 x 5
= 10
= (20 - 18 ) + (16 - 14 ) + ( 12 - 10 ) + ( 8 - 6 ) + ( 4 - 2 )
= 2 + 2 + 2 + 2 + 2
= 2 x 5
= 10
tính bằng cách nhanh nhất 10 + 12 + 14 + 16 + 18 + 20 = ? tính bằng cách nào
10 + 12 + 14 + 16 + 18 + 20
= ( 10 + 20 ) + ( 12 + 18 ) + ( 14 + 16 )
= 30 + 30 + 30 = 90
14/10-27/12+30/50+10/15+16/48-75/100
Tính nhanh
=0 còn cách lm mk ko bt
\(=\frac{7}{5}-\frac{27}{12}+\frac{3}{5}+\frac{2}{3}+\frac{1}{3}-\frac{3}{4}\)
\(=\frac{7}{5}+\frac{3}{5}+\frac{2}{3}+\frac{1}{3}-\frac{27}{12}-\frac{9}{12}\)
\(=2+1-3=0\)
\(\frac{14}{10}\)\(-\frac{27}{12}\)\(+\frac{30}{50}\)\(+\frac{10}{15}\)\(+\frac{16}{48}\)\(-\frac{75}{100}\)
\(=\frac{7}{5}\)\(+\frac{27}{12}\)\(+\frac{3}{5}\)\(+\frac{2}{3}\)\(+\frac{1}{3}\)\(-\frac{3}{4}\)
\(=\frac{7}{5}\)\(+\frac{3}{5}\)\(+\frac{2}{3}\)\(+\frac{1}{3}\)\(-\frac{27}{12}\)\(-\frac{9}{12}\)
\(=2+1-3\)
\(=0\)
tính nhanh:
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
= (2 + 8) + (4 + 6) + 10 + (12 + 18) + (14 + 16)
= 10 + 10 + 10 + 30 + 30
= 90
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 = 90 k mk nha mọi người
só đó là
90
ai k mình
mình k lại cho
ko hề dối trá gì cả
tính nhanh dãy tính sau
2-4+6-8+10-12+14-16+18