- Gửi lẻ câu hỏi ra nha bạn 2 3 câu 1 lần thôi .

a) (x-3)²-4=0

⇒ (x-3)²=4

⇒ hoặc x-3=2⇒x=5

hoặc x-3=-2⇒x=1

c) (x+4)²-(x+1)(x-1)=16

⇒ x²+8x+16-x²+1=16

⇒ 8x+17=16

⇒ 8x=-1

⇒ x=-1/8

a: =>33+x=71-36=35

=>x=2

b: =>(2x+6)=200-64=136

=>2x=130

=>x=65

c: =>x-19=76

=>x=95

e: =>x+9=39

=>x=30

f: =>x-8=20

=>x=28

g: =>2x=5*9+49=45+49=94

=>x=47

a: Ta có: \(\left(x+2\right)^2+\left(2x-1\right)^2-\left(x-3\right)^2=36\)

\(\Leftrightarrow x^2+4x+4+4x^2-4x+1-x^2+6x-9=36\)

\(\Leftrightarrow4x^2+6x-4-36=0\)

\(\Leftrightarrow4x^2+6x-40=0\)

\(\text{Δ}=6^2-4\cdot4\cdot\left(-40\right)=676\)

Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:

\(\left\{{}\begin{matrix}x_1=\dfrac{-6-26}{8}=-4\\x_2=\dfrac{-6+26}{8}=\dfrac{5}{2}\end{matrix}\right.\)

a) \(3\left(x+2\right)^2+\left(2x-1\right)^2-7\left(x-3\right)\left(x+3\right)=36\)

\(\Leftrightarrow3\left(x^2+4x+4\right)+\left(4x^2-4x+1\right)-7\left(x^2-9\right)=36\)

\(\Leftrightarrow3x^2+12x+12+4x^2-4x+1-7x^2+63=36\)

\(\Leftrightarrow8x+76=36\)

\(\Leftrightarrow8x=-40\)

\(\Leftrightarrow x=-5\)

\(a,\left(2x+1\right)^2-4\left(x+2\right)^2=9\\ \Leftrightarrow4x^2+4x+1-4\left(x^2+4x+4\right)-9=0\\ \Leftrightarrow4x^2-4x^2+4x-16x+1-16-9=0\\ \Leftrightarrow-12x=24\\ \Leftrightarrow x=\dfrac{24}{-12}=-2\\ b,\left(x+3\right)^2-\left(x-4\right)\left(x+8\right)=1\\ \Leftrightarrow x^2+6x+9-\left(x^2+4x-32\right)=1\\ \Leftrightarrow x^2-x^2+6x-4x=1-9-32\\ \Leftrightarrow2x=-40\\ \Leftrightarrow x=-20\\ c,3\left(x+2\right)^2+\left(2x-1\right)^2-7\left(x+3\right)\left(x-3\right)=36\\ \Leftrightarrow3\left(x^2+4x+4\right)+\left(4x^2-4x+1\right)-7\left(x^2-9\right)=36\\ \Leftrightarrow3x^2+12x+12+4x^2-4x+1-7x^2+63=36\\ \Leftrightarrow3x^2+4x^2-7x^2+12x-4x=36-12-1-63\\ \Leftrightarrow8x=-40\\ \Leftrightarrow x=\dfrac{-40}{8}=-5\)

a: \(\Leftrightarrow4x^2+4x+1-4\left(x^2+4x+4\right)-9=0\)

\(\Leftrightarrow4x^2+4x-8-4x^2-16x-16=0\)

=>-12x-24=0

=>-12x=24

hay x=-2

b: \(\Leftrightarrow x^2+6x+9-x^2-4x+32=1\)

=>2x=1-41=-40

hay x=-20

c: \(\Leftrightarrow3x^2+12x+12+4x^2-4x+1-7\left(x^2-9\right)=36\)

\(\Leftrightarrow7x^2+8x+13-7x^2+63=36\)

=>8x=-40

hay x=-5

c, (2\(\times\) \(x\) - 3) \(\times\) 5 = 4

    2 \(\times\) \(x\) - 3       = \(\dfrac{4}{5}\)

     2 \(\times\) \(x\)            = 0,8 + 3

      2\(x\)                = 3,8

        \(x\)                 = \(3,8\) : 2

        \(x\)                 = 1,9 

d, 1 + 3 + 5 +....+\(x\)   = 36

    (\(x\) + 1)\(\times\) \(x\): 2      = 36

     (\(x+1\)) \(\times\)\(x\)         = 72 

     (\(x+1\))\(\times\)\(x\)           = 8 x 9

      \(x\)                         = 8

a) (X - 5) x 4 = 36

⇒         X - 5 = 36 : 4

⇒         X - 5 = 9

⇒              X = 9 + 5

⇒              X = 14

     Vậy X = 14 

b) (48 - X) x 2 = 14

⇒         48 - X = 14 : 2

⇒         48 - X = 7

⇒                X = 48 - 7

⇒                X = 41

    Vậy X = 41

1: \(=6x^2+2x-15x-5-x^2+6x-9+4x^2+20x+25-27x^3-27x^2-9x-1\)

=-27x^3-18x^2+4x+10

2: =4x^2-1-6x^2-9x+4x+6-x^3+3x^2-3x+1+8x^3+36x^2+54x+27

=7x^3+37x^2+46x+33

5:

\(=25x^2-1-x^3-27-4x^2-16x-16-9x^2+24x-16+\left(2x-5\right)^3\)

\(=8x^3-60x^2+150-125+12x^2-x^3+8x-60\)

=7x^3-48x^2+8x-35