1 If you mix red with blue, you get purple

2 If they Arsenal wins, they will be on the top of the league

3 If it rains we will cancell the match

4 If you take the first bus, you will get there on time

5 If you need more helpers, I can try to get some time off work 

6 Mary might deliver your parcel if you ask her

7 If I were 20, I would travel around the world

8 If Jim lent us his car, we could go to the party

9 We would save 3.50 a day of we didn't eat any lunch

10 If Burglar broke into my house, they wouldn't find any money

Ngu

đánh nó mn ơi ''concau'' ý

Lời giải:

a. $(x-2)^3+(x+2)^3-6x(x+2)(x-2)$

$=x^3-6x^2+12x-8+(x^3+6x^2+12x+8)-6x(x^2-4)$

$=2x^3+24x-6x^3+24x=-4x^3+48x$

b.

$(2x-y)^3+(2x+y)^3$

$=8x^3-12x^2y+6xy^2-y^3+8x^3+12x^2y+6xy^2+y^3$

$=16x^3+12xy^2$

c.

$(x-2)(x+2)-(x^2+2x+4)(x-2)$

$=(x^2-4)-(x^3-2^3)=x^2-4-x^3+8=x^2-x^3+4$

a: =>2x-3x^2-x<15-3x^2-6x

=>x<-6x+15

=>7x<15

=>x<15/7

b: =>4x^2-24x+36-4x^2+4x-1>=12x

=>-20x+35>=12x

=>-32x>=-35

=>x<=35/32

\(a,2x-x\left(3x+1\right)< 15-3x\left(x+2\right)\\ \Leftrightarrow2x-3x^2-x< 15-3x^2-6x\\ \Leftrightarrow3x^2-3x^2+2x+6x-x< 15\\ \Leftrightarrow7x< 15\\ \Leftrightarrow x< \dfrac{15}{7}\)

Vậy S={-∞; 15/7}

\(b,4\left(x-3\right)^2-\left(2x-1\right)^2\ge12x\\ \Leftrightarrow4\left(x^2-6x+9\right)-\left(4x^2-4x+1\right)-12x\ge0\\ \Leftrightarrow4x^2-4x^2-24x+4x-12x\ge-36+1\\ \Leftrightarrow-32x\ge-35\\ \Leftrightarrow x\le\dfrac{35}{32}\)

Vậy S={-∞; 35/32]

`5,`

`a,`

`P(x)=x^5-2x^4+4x^3-x^5-3x^3+2x-5`

`= (x^5-x^5)-2x^4+(4x^3-3x^3)+2x-5`

`= -2x^4+x^3+2x-5`

Bậc của đa thức: `4`

`b,`

Hệ số cao nhất của đa thức: `-2`

`c,`

Hệ số tự do của đa thức: `-5.`

Bạn chú ý môn học.

tạm thời cái đề bài là tìm x vậy

tiếp tục thui

=) (6x-10)-(6x-3)\(⋮\)2x-1

=)6x-10-6x+3\(⋮\)2x-1

=) (6x-6x)-(10-3)\(⋮\)2x-1

=)0-7\(⋮\)2x-1

=)-7\(⋮\)2x-1=)2x-1\(\in\)Ư(-7)={-7;-1;1;7}

=)2x\(\in\){-6;0;2;8}

=)x\(\in\){-3;0;1;4}

x=115

\(230-\left(2x-8\right)=2^3\\ \Rightarrow230-\left(2x-8\right)=8\\ \Rightarrow2x-8=222\\ \Rightarrow2x=230\\ \Rightarrow x=115\)

230 - 2x + 8 = 8

238 - 2x = 8

- 2x = -230

x = 115

Bài giải:

b) 15 - 3 . |2x - 1| = 6

=> 12 . |2x - 1| = 6

=> |2x - 1| = 6 : 12

=> |2x - 1| = 0,5

=> 2x - 1 = 0,5 hoặc 2x - 1 = -0,5

     2x - 1 = 0,5                                            2x - 1 = -0,5

     2x = 0,5 + 1                                           2x = -0,5 + 1

     2x = 1,5                                                 2x = 0,5

     x = 1,5 : 2 = 0,75                                    x = 0,5 : 2 = 0,25

Vậy x = {0,75 ; 0,25}

c)2.|x| - 7 = 27

=> 2.|x| = 27 + 7

=> 2.|x| = 34

=> |x| = 34 : 2

=> |x| = 17

=> x = 17 hoặc x = -17

b , 15 -3 | 2x -1  | = 6

3 | 2x -1 |             = 15 -6

3 | 2x -1 |            =9

|2x -1 |                = 9 : 3

|2x -1 |                =3

suy ra 2x -1 thuoc { 3 ; -3 }

xet 2 truong hop

truong hop 1

2x -1 = 3

2x     =3+1

2x     = 4

x       = 4 : 2

x      = 2

c , 2| x | - 7     = 27

2 | x |              =27+7

2 | x |              =    34

   | x |             = 34 :2

   | x |             = 17

suy ra x thuoc { 17 ; 17 }

chuc ban hoc tot