tính nhanh:
(7!+5!) : (43.24)
tính = cách hợp lí nhất
43.37+57.61+43.24
43x37+57x61+43x24
=43x(37+24)+57x61
=61x43+61x57
=61x(43+57)
=61x100
=6100
Tinh bang cach hop li:
a, 47.33 + 47 + 66.47
b, 24.57 + 43.24
c, 387.2694 + 7305.387 + 387
d, 563.78 - 26.563 + 563.48
ai nhanh dc tik :P
a) \(47.33+47+66.47=47.\left(33+1+66\right)=47.100=4700\)
b) \(24.57+43.24=24.\left(57+43\right)=24.100=2400\)
c) \(387.2694+7305.387+387=387.\left(2694+7305+1\right)=387.10000=3870000\)
d) \(563.78-26.563+563.48=563.\left(78-26+48\right)=563.100=56300\)
a. 47.33 + 47 + 66.47
= 47.(33 + 1 + 66)
= 47 . 100
= 4700
b. 24.57 + 43.24
= 24. (57 + 43)
= 24 . 100
= 2400
c. 387 . 2694 + 7305.387 + 387
= 387. (2694 + 7305 + 1)
= 387 . 10000
= 3870000
d. 563 . 78 - 26.563 + 563.48
= 563. (78 - 26 + 48)
= 563 . 100
= 56300
a) 47.33 + 47 + 66.47 = 47 .(33 + 1 + 66)
= 47 . 100 = 4700
b) 24 . 57 + 43 . 24 = 24.( 57 + 43)
= 24 . 100 = 2400
c) 387 . 2694 + 7305 .387 . 387
= 387 . (2694 + 7305 + 1)
= 387 . 10000 = 3870000
d) 563 . 78 - 26.563 + 563.48
= 563.(78 - 26 + 48)
= 563 . 100 = 56300
Tính hợp lí:
a) 13.57 + 43.13
b) 39.28 + 39.72
c)345.67 - 245.67
d) 123.34 + 123.26 + 123.40
e) 974.34 + 974.96 - 974.30
f) 37.148 - 37.53 + 37.5
g) 47.173 + 47 + 66.47
h) 24.57 + 43.24
i) 387.2694 + 7305.387 + 387
a) 13 . 57 + 43.13 = 13.(57 + 43)
= 13 . 100 = 1300
b) 39 . 28 + 39 . 72 = 39 . (28 + 72)
= 39 . 100 = 3900
c) 345 . 69 - 245 . 67 = (345 - 245) . 67
= 100 . 67 = 6700
d) 123 . 34 + 123 . 26 + 123. 40 = 123 . (34 + 26 + 40)
= 123 . 100 = 12300
e) 974 . 34 + 974 . 96 - 974 . 30 = 974 . (34 + 96 - 30)
= 974 . 100 = 97400
f) 37 . 148 - 37 . 53 + 37 . 5 = 37 . (148 - 53 + 5)
= 37 . 100 = 3700
9) 47 . 173 + 47 + 66.47 = 47 . (173 + 1 + 66)
= 47 . 240 = 11280
h, i ) tự làm
Tinh hop li:
47.173 + 47- 47.74
47.33 + 47 + 66.47
24.57 + 43.24
387.2694 + 7305.387 + 387
12.19 + 12
195.56 + 43.105 + 195
47.173 + 47 - 47.74
= 47.( 173 + 1 - 74 )
= 47. 100
= 4700
47.33 + 47 + 66.47
24.57 + 43.24
387.2694 + 7305.387 + 387
12.19 + 12
195.56 + 43.105 + 195
Tính nhanh
1/7 . 5/9 + 5/9 . 1/7 +5/9 . 3/7
Ai nhanh mk tick
\(\frac{1}{7}.\frac{5}{9}+\frac{5}{9}.\frac{1}{7}+\frac{5}{9}.\frac{3}{7}\)
\(=\frac{5}{9}.\left(\frac{1}{7}+\frac{1}{7}+\frac{3}{7}\right)\)
\(=\frac{5}{9}.\frac{5}{7}=\frac{25}{63}\)
học vui!
= 5/9 . ( 1/7 + 1/7 + 3/7 )
= 5/9 . 5/7
= 25/63
Tk nha !!
Tính nhanh 2/7+12/7+4×2/7-2/5×5/7
\(=\dfrac{2}{7}+\dfrac{12}{7}+4\times\dfrac{2}{7}-\dfrac{2}{7}\\ =\dfrac{2}{7}\times\left(1+4-1\right)+\dfrac{12}{7}\\ =\dfrac{2}{7}\times4+\dfrac{12}{7}\\ =\dfrac{8}{7}+\dfrac{12}{7}=\dfrac{12+8}{7}=\dfrac{20}{7}\)
Tính nhanh
5/7×4+5/7+2×5/7+15/7
\(\frac{5}{7}.4+\frac{5}{7}+2.\frac{5}{7}+\frac{15}{7}=\frac{5}{7}.4+\frac{5}{7}+2.\frac{5}{7}+3.\frac{5}{7}\)
\(=\frac{5}{7}.\left(4+1+2+3\right)\)
\(=\frac{5}{7}.10=\frac{50}{7}\)
Tính nhanh
5/7×4+5/7+2×5/7+15/7
= 5/7 x [ 4 + 2 + 15/7 ]
=5/7 x 57/7
=399/49
- Mình không chắc là đúng đâu.
Tính nhanh :
1\(\dfrac{4}{5}\) + 2\(\dfrac{5}{7}\) + 3\(\dfrac{4}{5}\) + 4\(\dfrac{5}{7}\)
Giúp mik nhanh với mik đang cần gấp
\(1\dfrac{4}{5}+2\dfrac{5}{7}+3\dfrac{4}{5}+4\dfrac{5}{7}\)
\(\text{=}\left(1\dfrac{4}{5}+3\dfrac{4}{5}\right)+\left(2\dfrac{5}{7}+4\dfrac{5}{7}\right)\)
\(\text{=}1+3+\left(\dfrac{4}{5}+\dfrac{4}{5}\right)+2+4+\left(\dfrac{5}{7}+\dfrac{5}{7}\right)\)
\(\text{=}10+\dfrac{8}{5}+\dfrac{10}{7}\text{=}131\dfrac{1}{35}\)