<span>Раскройте скобки и упростите выражение .
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![1) 3(a-b)-2(a+b)=3a-3b-2a-2b=a-5b \\ 2) 4(x+y)+5(2x-y)=4x+4y+10x-5y=14x-y \\ 3) 2,4 (c-3d)-1,3(2c-d)=2.4c-7.2d-2.6c+1.3d=-0.2c-5.9d \\ 4) - \frac{3}{4} ( \frac{1}{2} m + n) - \frac{1}{4} (3m+n)=- \frac{3}{8}m- \frac{3}{4}n- \frac{3}{4}m- \frac{1}{4}n= -1 \frac{1}{8}m-n](https://tex.z-dn.net/?f=1%29+3%28a-b%29-2%28a%2Bb%29%3D3a-3b-2a-2b%3Da-5b+%5C%5C+2%29+4%28x%2By%29%2B5%282x-y%29%3D4x%2B4y%2B10x-5y%3D14x-y+%5C%5C+3%29+2%2C4+%28c-3d%29-1%2C3%282c-d%29%3D2.4c-7.2d-2.6c%2B1.3d%3D-0.2c-5.9d++%5C%5C+4%29+-+%5Cfrac%7B3%7D%7B4%7D+%28+%5Cfrac%7B1%7D%7B2%7D+m+%2B+n%29+-++%5Cfrac%7B1%7D%7B4%7D+%283m%2Bn%29%3D-+%5Cfrac%7B3%7D%7B8%7Dm-+%5Cfrac%7B3%7D%7B4%7Dn-+%5Cfrac%7B3%7D%7B4%7Dm-+%5Cfrac%7B1%7D%7B4%7Dn%3D+-1+%5Cfrac%7B1%7D%7B8%7Dm-n+)
<span>Раскройте скобки, приведите подобные слагаемые.
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![1)(3x+y)-(-x-4y) =3x+y+x+4y =4x+5y \\ 2) ( m + n ) - ( m - n) = m + n - m + n=2n \\ 3) (x + 6y) - ( 8x - 7y)=x + 6y - 8x + 7y=-7x+13y \\ 4) (m + 3 ) - ( 6m + 5) - (m - 1)=m + 3 - 6m - 5 - m + 1=-6m-1 \\ 5) (x - y ) + ( x - y ) - (2x + y) =x - y + x - y - 2x - y =-3y \\ 6) (0,2x - 3) - (x - 2 ) - (0,4x - 1) =0,2x - 3 - x + 2 - 0,4x +1 = \\ =-1.2x](https://tex.z-dn.net/?f=1%29%283x%2By%29-%28-x-4y%29+%3D3x%2By%2Bx%2B4y+%3D4x%2B5y+%5C%5C+2%29+%28+m+%2B+n+%29+-+%28+m+-+n%29+%3D+m+%2B+n++-++m+%2B+n%3D2n++%5C%5C+3%29+%28x+%2B+6y%29+-+%28+8x+-+7y%29%3Dx+%2B+6y+-++8x+%2B+7y%3D-7x%2B13y+%5C%5C+4%29+%28m+%2B+3+%29+-+%28+6m+%2B+5%29+-+%28m+-+1%29%3Dm+%2B+3++-++6m+-+5+-+m+%2B+1%3D-6m-1+%5C%5C+5%29+%28x+-+y+%29+%2B+%28+x+-+y+%29+-+%282x+%2B+y%29+%3Dx+-+y++%2B++x+-+y++-+2x+-+y+%3D-3y+%5C%5C+6%29+%280%2C2x+-+3%29+-+%28x+-+2+%29+-+%280%2C4x+-+1%29+%3D0%2C2x+-+3+-+x+%2B+2++-+0%2C4x+%2B1+%3D+%5C%5C+%3D-1.2x)
Узнаем площадь улицы, умножив ширину на длину:
800*15=12000 м2
Составим пропорцию
12000 м2 : Х т = 100 м2 : 3 т
х=12000*3:100=360 т
Ответ: 360 т.
На кубе ABCDA1B1C1D1 расставим числа следующим образом:
AB − 10, BC − 5, CD − 7, AD − 4,
A1B1 − 3, B1C1 − 9, C1D1 − 6, A1D1 − 8,
AA1 − 2, BB1 − 11, CC1 − 1, DD1 − 12.
На каждой грани куба сумма чисел равна 26.
Можно.
<span>Дано:
Продано -
![\frac{1}{2}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B2%7D+)
сукна←
Продано - </span><span>
![\frac{4}{5}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B5%7D+)
от →↑
Остаток - 3 м
Было - ? м сукна
Решение
1) </span><span>
![\frac{1}{2}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B2%7D+)
*</span><span>
![\frac{4}{5}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B5%7D+)
= </span><span>
![\frac{1*4}{2*5}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%2A4%7D%7B2%2A5%7D+)
= </span><span>
![\frac{4}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B10%7D+)
= </span><span>
![\frac{2}{5}](https://tex.z-dn.net/?f=+%5Cfrac%7B2%7D%7B5%7D+)
- (сукна) - продано второму покупателю.
2) </span>
![\frac{1}{2}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B2%7D+)
+<span>
![\frac{2}{5}](https://tex.z-dn.net/?f=+%5Cfrac%7B2%7D%7B5%7D+)
= </span>
![\frac{1*5}{2*5}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%2A5%7D%7B2%2A5%7D+)
+<span>
![\frac{2*2}{2*5}](https://tex.z-dn.net/?f=+%5Cfrac%7B2%2A2%7D%7B2%2A5%7D+)
= </span><span>
![\frac{5}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B5%7D%7B10%7D+)
+ </span><span>
![\frac{4}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B10%7D+)
= </span><span>
![\frac{9}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B9%7D%7B10%7D+)
(сукна) - было продано.
3) 1-</span><span>
![\frac{9}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B9%7D%7B10%7D+)
= </span><span>
![\frac{10}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B10%7D%7B10%7D+)
- </span><span>
![\frac{9}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B9%7D%7B10%7D+)
= </span><span>
![\frac{1}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B10%7D+)
(сукна) - остаток, который составляет 3 метра.
4) 3:</span><span>
![\frac{1}{10}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B10%7D+)
= 3*10=30 (м) сукна было в куске.
ОТВЕТ: в куске было 30 метров сукна.
</span>
8, -3, 1, -1, -15 ///////