mình gợi ý nhé 1 

1.  là so sánh với 1 

2 . so sánh với 0

3 . rút gọn đi rồi quy đồng lên sau đó so sánh

\(8x^2+6x^3=2x^2\left(4+3x\right)\)

\(x^3-5x^2-4x+20=x^2\left(x-5\right)-4\left(x-5\right)=\left(x^2-4\right)\left(x-5\right)=\left(x-2\right)\left(x+2\right)\left(x-5\right)\)

\(x^2-9y^2-4x+4=\left(x^2-4x+4\right)-\left(3y\right)^2=\left(x-2\right)^2-\left(3y\right)^2=\left(x-2-3y\right)\left(x-2+3y\right)\)

a: \(8x^2+6x^3=2x^2\left(4+3x\right)\)

b: \(x^3-5x^2-4x+20\)

\(=x^2\left(x-5\right)-4\left(x-5\right)\)

\(=\left(x-5\right)\left(x-2\right)\left(x+2\right)\)

c: \(x^2-4x+4-9y^2\)

\(=\left(x-2\right)^2-9y^2\)

\(=\left(x-2-3y\right)\left(x-2+3y\right)\)

15 - (-x+1)=(-37)+87 = 50

(-x+1)= 15 - 50 = -35

-x = -35 - 1 = -36

x= -36 : (-1)= 36

`#3107.101107`

`15 - (-x + 1) = (-37) + 87`

`\Rightarrow 15 + x - 1 = 87 - 37`

`\Rightarrow 14 + x = 50`

`\Rightarrow x = 50 - 14`

`\Rightarrow x = 36`

Vậy, `x = 34.`

15-(-x+1)=50

(-x)+1=15-50

(-x)+1=(-35)

(-x)=(-35)-1

(-x)=(-36)

x=36

Ta có:

     (2 - 3x)(x + 8) = (3x - 2)(3 - 5x)

⇔ (2 - 3x)(x + 8) - (3x - 2)(3 - 5x) = 0

⇔ (2 - 3x)(x + 8) + (2 - 3x)(3 - 5x) = 0

⇔ (2 - 3x)(x + 8 + 3 - 5x) = 0

⇔ (2 - 3x)(11 - 4x) = 0

⇔ 2 - 3x = 0 hay 11 - 4x = 0

⇔ 2 = 3x hay 11 = 4x

⇔ x = \(\dfrac{2}{3}\) hay x = \(\dfrac{11}{4}\)

Vậy tập nghiệm của pt S = \(\left\{\dfrac{2}{3};\dfrac{11}{4}\right\}\)

khum bt mới lớp 5 hoi à(k10)

<=> (2-3x ) (x+8) + (2-3x ) (3-5x)=0
<=> (2-3x ) ( x+8 +  3-5x ) =0 
<=> (2-3x ) ( 11 - 4x ) = 0
 => 2-3x  =0 hoặc 11-4x =0  
       3x = 2            4x =11
         x = 2/3         x    = 11/4

c: =53*55+53*1+53*145

=53*201=10653

d: Số số hạng là (126-3)/3+1=42 số

Tổng là (126+3)*42/2=129*21=2709

a) 41. 36+ 59. 90 + 41. 84 + 59. 30

= 41 . (36 + 84) + 59 . (90 + 30)

= 41 . 120 + 59 . 120

= 120 . ( 41 + 59 )

= 120 . 100

= 12000

b) 4. 51 . 7 + 2 . 86 .7 + 6 . 4 . 7

= 28 . 51 + 2 . 43 . 2 . 7 + 6 . 4 . 7

= 28 . 51 + 28 . 43 + 28 . 6

= 28 . ( 51 + 43 + 6 )

= 28 . 100

= 2800

c) ( 4.7 ) . 5 + ( 4.7 ) . 43 + ( 4.7) - 6

= 28 . 5 + 28 .43 + 28 - 6

= 28 . (5 + 43 + 1) - 6

= 28 . 49 - 6

= 1372 - 6

= 1366.

d) 53 . 39 + 47 . 39 - 53 . 21 - 47 . 21

= 53 . (39 - 21) + 47. (39 - 21)

= (39 - 21) . ( 53 + 47 )

= 18 . 100

= 1800.

a: \(=\left(4xy^2+2xy^2\right)+\left(3x^2y-3x^2y\right)=6xy^2\)

b: \(=xy\left(\dfrac{1}{5}+\dfrac{1}{3}\right)+xy^2\left(\dfrac{4}{3}-\dfrac{2}{5}\right)=\dfrac{8}{15}xy+\dfrac{14}{15}xy^2\)

d: \(=\dfrac{-4}{9}\cdot\dfrac{3}{2}\cdot xy^2\cdot xy^3=-\dfrac{2}{3}x^2y^5\)

    -5 + (-37 - 45 + 51) - (-37 + 51)

=  -5  - 37 - 45 + 51 + 37 - 51

=  - (5 + 45) - (37 - 37) + (51 - 51)

= - 50 - 0 + 0

= - 50

  - (15 - 47 + 58) + (15 - 47 ) + 3

= - 15 + 47 - 58 + 15 - 47 + 3

= (-15 + 15) + (47 - 47) - (58 - 3)

= 0 + 0 - 55

= - 55

  (53 - 45 - 49) - (53 + 45 - 49)

= 53 -  45 - 49 - 53 - 45 + 49

= (53 - 53) + (-49 + 49) - (45 + 45)

= 0 + 0 - 90

= - 90 

    13 - 15 + 49 - 13 + 15 - 48

=  (13 - 13) + (-15 + 15) + (49 - 48)

= 0 + 0 + 1

=  1 

15+13 -15-13 +49-48