A

A

A

A

A

C

a: \(M=\dfrac{18+5x+15+3x-9}{\left(x+3\right)\left(x-3\right)}=\dfrac{8x+24}{\left(x+3\right)\left(x-3\right)}=\dfrac{8}{x-3}\)

b: Thay x=11 vào M, ta được:

\(M=\dfrac{8}{11-3}=1\)

a) \(M=\dfrac{18}{x^2-9}+\dfrac{5}{x-3}+\dfrac{3}{x+3}.\left(x\ne\pm3\right).\)

\(M=\dfrac{18}{\left(x-3\right)\left(x+3\right)}+\dfrac{5}{x-3}+\dfrac{3}{x+3}=\dfrac{18+5\left(x+3\right)+3\left(x-3\right)}{\left(x-3\right)\left(x+3\right)}\)

\(=\dfrac{18+5x+15+3x-9}{\left(x-3\right)\left(x+3\right)}=\dfrac{24+8x}{\left(x-3\right)\left(x+3\right)}\)

\(=\dfrac{8\left(3+x\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{8}{x-3}.\)

b) Thay \(x=11\left(TM\right)\) vào biểu thức M: 

\(\dfrac{8}{11-3}=\dfrac{8}{8}=1.\)

ai lm tr mình cho tích

A

A

A

\(96-4:\left[\left(11-9\right)^5:\left(7-5\right)^3\right]\)

\(96-4:\left[2^5:2^3\right]=96-4:\left[2^2\right]=96-4:4=96-1=95\)

96 - 4: [ (11 - 9)⁵ : ( 7 - 5)³ ] 

96 - 4 : [ 2⁵ : 2³ ]

96 - 4: 2²

= 96 - 4: 4

= 96 - 1

= 95 

a = 241/385

b = 53/72

c = 571/385

d = 533/231

4/9 x 3/8 + 5/8 = 1/6 + 5/8 = 19/24

1/3 : 1/6 - 5/11 = 2 - 5/11 = 17/11

1/6 : 1/4 x 9/8 = 2/3 x 9/8 = 3/4

Cái này là phân số hay phép chia vậy bạn

\(\dfrac{4}{9}\) x \(\dfrac{3}{8}\) + \(\dfrac{5}{8}\) = \(\dfrac{1}{6}\) + \(\dfrac{5}{8}\) = \(\dfrac{19}{24}\)

\(\dfrac{1}{3}\) : \(\dfrac{1}{6}\) - \(\dfrac{5}{11}\) = 2 - \(\dfrac{5}{11}\) = \(\dfrac{17}{11}\)

\(\dfrac{1}{6}\) : \(\dfrac{1}{4}\) x \(\dfrac{9}{8}\) = \(\dfrac{2}{3}\) x \(\dfrac{9}{8}\) = \(\dfrac{3}{4}\)

=(4x0.25)x(2x0.5)

=1x1=1