35-(27+x)=x-(28-13)
5/13 x 9/14 x 28/27 x 26/35
\(\dfrac{5}{13}\) \(\times\) \(\dfrac{9}{14}\) \(\times\) \(\dfrac{28}{27}\) \(\times\) \(\dfrac{26}{35}\)
= \(\dfrac{5}{13}\) \(\times\) \(\dfrac{9}{14}\) \(\times\) \(\dfrac{14\times2}{9\times3}\) \(\times\) \(\dfrac{13\times2}{5\times7}\)
= \(\dfrac{5\times9\times14\times13}{5\times9\times14\times13}\) \(\times\) \(\dfrac{2\times2}{3\times7}\)
= 1 \(\times\) \(\dfrac{4}{21}\)
= \(\dfrac{4}{21}\)
tìm x biết:x = 35 - 27 + 28 x = ?
tính hợp lí nhất :
1, 35 . ( 14 - 23 ) - 23 . ( 14 - 35 )
2 , 27 . ( 13 - 16 ) - 16 .( 13 - 27 )
3, 44 . (-36 ) + 22 . ( - 28 )
1.
\(35\times\left(14-23\right)-23\times\left(14-35\right)\)
\(=35\times14-35\times23-23\times14+23\times35\)
\(=\left(23\times35-35\times23\right)+14\times\left(35-23\right)\)
\(=0+14\times12\)
\(=168\)
2.
\(27\times\left(13-16\right)-16\times\left(13-27\right)\)
\(=27\times13-27\times16-16\times13+16\times27\)
\(=13\times\left(27-16\right)+\left(27\times16-16\times27\right)\)
\(=13\times11+0\)
\(=143\)
3.
\(44\times\left(-36\right)+22\times\left(-28\right)\)
\(=22\times2\times\left(-36\right)+22\times\left(-28\right)\)
\(=22\times\left(-72\right)+22\times\left(-28\right)\)
\(=22\times\left[\left(-72\right)+\left(-28\right)\right]\)
\(=22\times\left(-100\right)\)
\(=-2200\)
Chúc bạn học tốt
tính: 27/28 x 35/36 x 44/45 x...x 4949/4950
1 tìm số nguyên x biết :
A) x - 35 - (27-135) =2*(4-15)-82
B) 39-x+(28-(48-2*13))=27-48
C) (-54)-x-(126-(52-165))=85-(-22)
d) 2*x-84-(64-2.(34-6))=128-(-52)
Trả lời đúng rồi nhanh mik tik cho.. .nhanh nha
rút gọn
a) 19 x 28 - 19 x 3 / 5 x 3 + 5 x 35
b) 7 x 9 + 14 x 29 + 21 x 36 / 21 x 27 + 42 x 81 + 63 x 108
c) 11 x 13 - 22 x 26 / 22 x 26 - 44 x54
giúp tui với nha
a)19 x (28 - 3) / 5x (3+35 )
= 19 x 25 /5 x 38
= 475/190
= 5/2
còn mấy ý kia chung j đặt đấy nhé mik hơi lười
Tính hợp lý
a, - ( - 15 ) - ( +27 ) + ( + 27 ) + ( -15 ) + ( -29)
b, 12 - ( a + 105 - 13 ) + ( 4 + 105 - 13 )
c, ( 5 + 7 - 8 ) - ( 7 + 5 - 8 )
d, - 15 - ( -17 + 21 - 35 ) + ( -17 + 21 - 35)
e, 32 - ( -7 - 28 + 15 ) - ( 7 + | -28 | + 32 )
f, -1379 - ( -1379 - 27 )
Làm giùm, cần gấp.
Tìm x
a) x – 12 = 14
b) 2x – 13 = 3.17
c) x – 43 = 2.18
d) (x – 14).39 = 0
e) (13 – x).28 = 28
f) 22.(35 – x) = 22
g) x – 24 : 2 = 18
h) 400 + (275 – x) = 570
a) x – 12 = 14
x = 14 +12
x = 26
b) 2x – 13 = 3.17
2x = 51 + 13
2x = 64
x = 64 : 2
x = 32
c) x – 43 = 2.18
x = 36 +43
x = 79
d) (x – 14).39 = 0
x – 14 = 0
x = 14
e) (13 – x).28 = 28
13 – x = 1
13 – x = 1
x = 13 – 1
x = 12
f) 22.(35 – x) = 22
35 – x = 1
x = 35 – 1
x = 34
g) x – 24 : 2 = 18
x – 12 = 18
x = 39
h) 400 + (275 – x) = 570
275 – x = 570 – 400
275 – x = 170
x = 275 – 170
x = 105
Thực hiện phép tính :
a) 123 - 27 + 27 + 13 - 123
b) 175 + 25 + 13 + 15 - 175 - 25
c) 53 x 39 + 47 x 39 + 53 x 21 + 47 x 21
d) 49 x 35 + 49 x 16 - 49 x 61
a) `123 - 27 + 27 + 13 - 123`
`= (123 - 123) + (27 - 27) + 13`
`= 0 + 0 + 13`
`= 13`
`---`
b) `175 + 25 + 13 + 15 - 175 - 25`
`= (175-175)+(25-25)+25+13`
`=0+0+25+13`
`=28`
`---`
c) \(53\times39+47\times39+53\times21+47\times21\)
\(=\text{[}\left(53+47\right)\times39]+\left[\left(53+47\right)\times21\right]\)
\(=\left(100\times39\right)+\left(100\times21\right)\)
\(=3900+2100\)
`=6000`
`---`
d) \(49\times35+49\times16-49\times61\)
`=` \(49\times\left(35+16-61\right)\)
`=` \(49\times\left(-10\right)\)
`=-490`