tính nhanh
1+2+3+4+5+6+7+8+9=
10+20+30+40+50+60+70+80+90=
1237+2249+1763+2251=
trình bày rõ ràng,nhanh thì tk và phải đúng
nhớ là tính nhanh đấy
trả lời nha
tính bằng cách thuận tiên
a) 1/10 + 2/20 + 3/30 + 4/40 + 5/50 + 6/60 + 7/70 + 8/80 + 9/90
b) 3,72 + 2,05 + 6,28 + 7,95
nhớ viết ra rõ ràng cho mk nha
ai nhanh mk tk cho
cảm ơn !
b) 3,72 + 2,05 + 6,28 + 7,95
= ( 3,72 + 6,28 ) + ( 2,05 + 7,95 )
= 10 + 10
= 20
a) 1/10+2/20+3/30+4/40+5/50+6/60+7/70+8/80+9/90
=1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10
=1
b)3,72+2,05+6,28+7,95
=(3,72+6,28)+(2,05+7,95)
=10 +10
=20
a, =1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10
=1/10x9
=9/10
b, =(3,72+6,28)+(2,05+7,95)
=10+10
=20
Tính nhanh:
1/10+2/20+3/30+4/40+5/50+6/60+7/70+8/80+9/90=?
\(\frac{1}{10}+\frac{2}{20}+\frac{3}{30}+\frac{4}{40}+\frac{5}{50}+\frac{6}{60}+\frac{7}{70}+\frac{8}{80}+\frac{9}{90}\)
\(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}\)
\(=\frac{9}{10}\)
1/10=1/10 ; 2/20=1/10 .......9/90=1/10
1/10*10 =10/10=1
Rút gọn ta đc:
\(\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}\)\(\frac{1}{10}\)
=\(\frac{1}{10}\)x9=\(\frac{9}{10}\)
Tính nhanh:
a, 5+5+5+5+5+5+5+5+5+5=
b, 1+2+3+4+5+6+7+8+9=
c, 10+20+30+40+50+60+70+80+90=
Kb nha mình tk cho hiiiiiii
a,50 b,45 c,450
Mình không làm được vì bàn phím mình đang bị liệt dấu
a. 5+5+5+5+5+5+5+5+5+5=5x10=50
b.1+2+3+4+5+6+7+8+9=(1+9)+(2+8)+(3+7)+(4+6)+5
=10+10+10+10+5
=10x4+5
=40+5=45
c.10+20+30+40+50+60+70+80+90
=(10+90)+(20+80)+(30+70)+(40+60)+50
=100+100+100+100+50
=100x4+50
400+50
=450
thính nhanh:
a) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
b) 10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 + 100
ai nhanh mk sẽ tk
\(1+2+3+4+5+6+7+8+9+10\)\(10=55\)
\(10+20+30+40+50+60+70+80\)\(+90+100=550\)
K mình nhahải anh
Chúc bạn học giỏi
Tính nhanh :
1 / 10 + 2 / 20 + 3 / 30 + 4 / 40 + 5 / 50 + 6 / 60 + 7 / 70 + 8 / 80 + 9 / 90
Ai tk mk mk tk lại
1/10 + 2/20 + 3/30 + 4/40 + 5/50 + 6/60 + 7/70 + 8/80 + 9/90
= 1/10 + 1/10 + 1/10 + 1/10 + 1/10 + 1/10 + 1/10 + 1/10 + 1/10
= 1/10 x 9
= 9/10
1 / 10 + 2 / 20 + 3 / 30 + 4 / 40 + 5 / 50 + 6 / 60 + 7 / 70 + 8 / 80 + 9 / 90
= 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10
= 1 / 10 x 9
= 9 / 10
\(\frac{1}{10}+\frac{2}{20}+\frac{3}{30}+\frac{4}{40}+\frac{5}{50}+\frac{6}{60}+\frac{7}{70}+\frac{8}{80}+\frac{9}{90}\)
\(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}\)
\(=\frac{1}{10}\times9\)
\(=\frac{9}{10}\)
tính nhanh:
1+2+3+4+5+6+7+8+9
10+20+30+40+50+60+70+80+90
nhanh, đúng, đủ mới tick
1+2+3+4+5+6+7+8+9
=(1+9)+(2+8)+(3+7)+(4+6)+5
=10+10+10+10+5
=10.4+5
=45
10+20+30+40+50+60+70+80+90
=10.(1+2+3+4+5+6+7+8+9+)
=10.45
=450
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 ( có 9 số)
= (1 + 9) × 9 : 2
= 10 × 9 : 2
= 90 : 2
= 45
10 + 20 + 30 + 40 + 60 + 60 + 70 + 80 + 90
= 10 × (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9)
= 10 × 45
= 450
11+12+13+14+15+16+17+18+19=
10+20+30+40+50+60+70+80+90=
1+2+3+4+5+6+7+8+9=
Kb nha tk cho câu hỏi nhanh nhất kb nhaaaa
11+12+13+14+15+16+17+18+19=135
10+20+30+40+50+60+70+80+90=450
1+2+3+4+5+6+7+8+9=45
Tính nhanh:
a,1/4+2/5+6/8+9/15+8/1
b,1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+10/20
c,1/10+4/20+9/30+16/40+25/50+36/60+49/70+64/80+81/90
Tính nhanh:
a,1/4+2/5+6/8+9/15+8/1
b,1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+10/20
c,1/10+4/20+9/30+16/40+25/50+36/60+49/70+64/80+81/90