a/ M = (71+x)-(-24+x)+(-35-x) = 71 + x + 24 - x - 35 - x = (71 + 24 - 35) - x = 95 - 35 - x = 60 - x

b/ N=x-34-[(15+x)-(23-x)] = x - 34 - (15 + x - 23 + x) = x - 34 - (-8 + 2x) = x - 34 + 8 - 2x = -26 - x

\(a,M=\left(71+x\right)-\left(-24+x\right)+\left(-35-x\right)\)

        \(=71+x+24-x-35-x\)

        \(=60-x\)

\(b,N=x-34-\left[\left(15+x\right)-\left(23-x\right)\right]\)

       \(=x-34-\left(15+x-23+x\right)\)

       \(=x-34-15-x+23-x\)

       \(=-26-x\)

a) M=(71+x)-(-24+x)+(-35-x)

      = 71+x-(-24)-x+(-35)-x

      = (-24+71)+(-35)+(x-x-x)

      = 47+(-35)+(-x)

      = 12+(-x)

      = 12-x

 Vậy M=12-x

kết quả là x+60

a/ (71+x) - [(-24) - x] + [(-35) - x ]=71+x+24+x-35-x=x+60

b/ x - 34 - [(15 + x) - (23 - x)]=x-34-15-x-23+x=x-72

c/ 26 - [(-x) + 126 - 13) + [(-113) + x]=26+x-126+13-113+x=2x-200=2(x-100)

A = ( 71 + x ) - ( -24 - x ) + ( -35 - x )

= 71 + x - ( -24 ) + x + ( -35 ) + x 

= 71 - ( -24 ) + ( -35 ) + x . 3

= 60 + 3x 

= 3 ( 20 + x ) 

B = x - 34 - [ ( 15 + x ) - ( 23 - x ) ]

= x - 34 - [ 15 + x - 23 + x ]

= x - 34 - ( 15 - 23 ) - 2x

= x - 34 - ( -8 ) - 2x

= x - 26 - 2x 

= ( -x )  - 26 

C ) tương tự 

a. x+60

b. -x-26

c.10

Ta có: \(\frac{\left(3+\sqrt{x}\right)^2-\left(2-\sqrt{x}\right)^2}{1+2\sqrt{x}}=\frac{\left(3+\sqrt{x}+2-\sqrt{x}\right)\left(3+\sqrt{x}-2+\sqrt{x}\right)}{1+2\sqrt{x}}\)

\(=\frac{5\left(1+2\sqrt{x}\right)}{1+2\sqrt{x}}=5\)

k và Kb với tớ nha!

mk chỉ làm ý A thui nha

\(A=\left(71+x\right)-\left(-24-x\right)+\left(-35-x\right)\)

\(A=71+x+24+x+\left(-35\right)-x\)

\(A=\left[71+24+\left(-35\right)\right]+\left(x+x-x\right)\)

\(A=60+x\)

Vậy \(A=60+x\)

\(a,A=\left(71+x\right)-\left(-24-x\right)+\left(-35-x\right)\)

       \(=71+x+24+x-35-x\)

       \(=60+x\)

\(b,B=x-34-\left[\left(15+x\right)-\left(23-x\right)\right]\)

       \(=x-34-\left(15+x-23+x\right)\)

       \(=x-34-15-x+23-x\)

       \(=-x-26\)

a) A = (71 + x) - (-24 - x) + (-35 - x)

A = 71 + x + 24 + x + (-35) - x

A = (x + x - x) + (71 + 24 + (-35)
A = x + 60

b) B = x - 34 - [(15 + x) - (23 - x)]

B = x - 34 - [15 + x - 23 + x]

B = x - 34 - 15 - x + 23 - x

B = (x - x - x) + (-34 - 15 + 23)

B = -x + (-26)

c) C = (-15 + |x|) + (25 - |-x|)

C = (-15) + x + 25 - (-x)

C = (-15) + x + 25 + x

C = (x + x) + [(-15) + 25]

C = 2x + 10

M = (x + 3)(x² - 3x + 9) - (x³ + 54 - x) với x = 27

  = (x^3+27)-(x³ + 54 - x)

  =x^3+27-x³ - 54 + x

  =27-54+x

  =-27+x

thay x=27 vào biểu thức trên ta có 

-27+x=-27+27=0

vậy M=0

Ta có: \(M=\left(x+3\right)\left(x^2-3x+9\right)-\left(x^3+54-x\right)\)

\(=x^3+27-x^3-54+x\)

\(=x-27\)

Thay x=27 vào biểu thức M=x-27, ta được:

M=27-27=0

Vậy: Khi x=27 thì M=0

\(a,x\ne\pm2\\ b,\\ =\dfrac{x^3-x\left(x+2\right)-2\left(x-2\right)}{x^2-4}\\ =\dfrac{x^3-x^2-2x-2x+4}{x^2-4}=\dfrac{x^3-4x-x^2+4}{x^2-4}\\ =\dfrac{x\left(x^2-4\right)-\left(x^2-4\right)}{x^2-4}=\dfrac{\left(x^2-4\right)\left(x-1\right)}{x^2-4}\\ =x-1\)