tính nhanh : 36:25+64:25
Tính nhanh :
25 x 64 + 25 x 36 = .......
25 x 64 + 25 x 36
= 25 x ( 64 + 36 )
= 25 x 100
= 2500
Tính nhanh 15 . 64 + 25 . 100 + 36 . 15 + 60 . 100
15 . 64 + 25 . 100 + 36 . 15 + 60 . 100
= (15 . 64 + 36 . 15) + (25 . 100 + 60 . 100)
= 15. (64 + 36) + 100. (25 + 60)
= 15 . 100 + 100 . 85
= 100 . (15 + 85)
= 100 . 100
= 10000
tính nhanh :
1/5+4/10+9/15+16/20+25/25+36/30+49/35+64/40+81/45
cần gấp mn !!!
Ta có: \(\dfrac{1}{5}+\dfrac{4}{10}+\dfrac{9}{15}+\dfrac{16}{20}+\dfrac{25}{25}+\dfrac{36}{30}+\dfrac{49}{35}+\dfrac{64}{40}+\dfrac{81}{45}\)
\(=\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}+\dfrac{5}{5}+\dfrac{6}{5}+\dfrac{7}{5}+\dfrac{8}{5}+\dfrac{9}{5}\)
\(=\dfrac{45}{5}=9\)
\(\dfrac{1}{5}+\dfrac{4}{10}+\dfrac{9}{15}+...+\dfrac{81}{45}\\ =\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+...+\dfrac{9}{15}\\ =\dfrac{\left(1+2+3+...+9\right)}{15}=\dfrac{\left(1+9\right)x9:2}{15}\\ =\dfrac{10x9:2}{15}=\dfrac{45}{15}=3\)
Tính nhanh 15 . 64 + 25 . 100 + 36 . 15 + 60 . 100
=15.(64+36)+100.(25+60)
=15.100+85.100
=100.(15+85)
=100.100
=10000
tính nhanh a) 46 + 17 + 54 b) 4 . 37 . 25 c) 87 . 36 + 87 . 64
a, ( 46 + 54 ) + 17 = 100 + 17 = 117
b, ( 4 . 25 ) . 37 = 100 . 37 = 3700
c, 87 . ( 36 + 64 ) = 87 . 100 = 8700
a,46+17+54
=(46+54)+17
=100+17
=117
b,4.37.25
=(4.25).37
=100.37
=3700
c,87.36+87.64
=87.(36+64)
=87.100
=8700
Chúc bạn học giỏi nha ^-^
Tính nhanh : 1/10 + 4/20 + 9/30 + 16/40 + 25/50 + 36/60 + 49/70 + 64/80 + 81/90
1/10 + 4/20 + 9/30 + 16/40 + 25/50 + 36/60 + 49/70 + 64/80 + 81/90
= 1/10 + 2/10 + 3/10 + 4/10 + 5/10 + 6/10 + 7/10 + 8/10 + 9/10
=(1+2+3+....+9) /10
=(1+9)x9:2 /10
=45/10=4,5
chắc chắn đúng đó
Tính bằng cách thuận tiện nhất :
a)5*25*216*4
b)4*37*25*16
c)36*28+36*82+64*69+64*41
d)42*53+42*36+42*11
e)37*45+56*37-37
h)17+17*81+18*17
ai nhanh nhất đc 3 tick nha
a ) 5 x 216 x 25 x 4 = 1080 x 100 = 108000
b ) 37 x 16 x 25 x 4 = 592 x 100 = 59200
c ) 36 x ( 28 + 82 ) + 64 x ( 69 + 41 ) = 36 x 110 + 64 x 110 = ( 36 + 64 ) x 110 = 100 x 110 = 11000
d ) 42 x ( 53 + 36 + 11 ) = 42 x 100 = 4200
e) 37 x 45 + 56 x 37 - 37 x 1 = 37 x ( 45 + 56 - 1 ) = 37 x 100 = 3700
h) 17 x 1 + 17 x 81 + 18 x 17 = 17 x ( 1 + 81 + 18 ) = 17 x 100 = 1700
Mik nhanh nhất đấy , nhớ click cho mik nha !!!!!!!!!!!!!!!!!!!
a) 5 x 25 x 216 x 4
= ( 5 x 216 ) x ( 25 x 4 )
= 1080 x 100
= 108000
b) 4 x 37 x 25 x 16
= ( 4 x 25 ) x ( 37 x 16 )
= 100 x 592
= 59200
a)=(25x4)x5x216=100x5x216=500x216=108000
b)=(4x25)x37x16=100x37x16=3700x16=59200
c)=[36x(28+82)]+[64x(69+41)]=[36x110]+[64x110]=110x(36+64)=110x100=11000
d)=42x(53+36+11)=42x100=4200
e)=37x(45+56-1)=37x100=3700
h)=17x(1+81+18)=17x100=1700
k mk nhá
a,
tìm x biết
x+36=98
x*8=56
b,
16+32
39+25
c, tính nhanh
36+69+31+64
12+78+25+75
ai nhanh mình tick
a ) x + 36 =98
x = 98 -36
x = 62
x * 8 = 56
x = 56 : 8
x = 7
b ) 16 + 32 = 48
39 + 25 = 64
c) tính nhanh :
36 + 69 + 31 + 64
= ( 36 + 64 ) + ( 69 + 31 )
= 100 + 100
= 200
12 + 78 + 25 + 75
= (12 + 78 ) + ( 25 + 75 )
= 90 + 100
= 190
a)62 va 7 b)48 va 64 c)200 vs 190
TK CHO MK NHA !
Tính nhanh:
1/5 + 4/10 +9/15 + 16/20 + 25/25 + 36/30 + 49/35 + 64/40 + 81/45
1/5 + 4/10 +9/15 + 16/20 + 25/25 + 36/30 + 49/35 + 64/40 + 81/45
=1/5 + 2/5 + 3/5 +...+ 9/5
=45/5=9
\(\frac{1}{5}+\frac{4}{10}+\frac{9}{15}+\frac{16}{20}+\frac{25}{25}+\frac{36}{30}+\frac{49}{35}+\frac{64}{40}+\frac{81}{45}\)
\(=\frac{1}{5}+\frac{1}{5}+\frac{3}{5}+\frac{4}{5}+\frac{5}{5}+\frac{6}{5}+\frac{7}{5}+\frac{8}{5}+\frac{9}{5}\)
\(=\frac{\left(9+1\right)\cdot9:2}{5}=\frac{45}{5}=9\)