ta có :

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

hay \(\left(25-2x\right)^3=25\times5=125=5^3\Leftrightarrow25-2x=5\Leftrightarrow2x=20\)

\(\Leftrightarrow x=10\)

( 25 - 2x )³ : 5 - 2⁴ = 3²

=> ( 25 - 2x )³ : 5 - 16 = 9

=> ( 25 - 2x )³ : 5 = 25

=> ( 25 - 2x )³ = 125

=> ( 25 - 2x )³ = 5³

=> 25 - 2x = 5

=> 2x = 20

=> x = 10

\(\left(25-2x\right)^3:5-2^4=3^2\)

\(\left(25-2x\right)^3:5-16=9\)

\(\left(25-2x\right)^3:5=9+16\)

\(\left(25-2x\right)^3:5=25\)

\(\left(25-2x\right)^3=25.5\)

\(\left(25-2x\right)^3=125\)

\(\left(25-2x\right)^3=5^3\)

\(\Rightarrow25-2x=5\)

\(2x=25-5\)

\(2x=20\)

\(x=20:2\)

\(x=10\)

                       Giai

a,  Với x>=5 thì ta có xpt: x-5 -3x=3 => -2x-5=3 => x=-4 (loại vì x bé hơn 5)

Với x<5 thì ta có pt :        5-x-3x=3 => 5-4x =3 =>x=1\2 (t\m)

         Vây x=1\2

b, Tương tụ nha pn...nhớ k nha

mình chưa hiểu mấy bạn ạ 

dsa=sgt

a)..

b)...

c)...

d)...

e) ?x?=0 nếu x=0

?x?=1nếu x=1 hoặc -1

ngodinhnghi3 sao ko trả lời câu hỏi của mình zậy hả mà câu hỏi của mình đâu có câu e) đâu mà

a: =2(3h15'+4h45')=2x8h=16h

b: =(24'30s+25'30s):5

=50':5=10'

1)5/7+7/9-2/3

=45/63+49/63-42/63

52/63

2)5/6 nhân 4/5 -17/30

=2/3-17/30

= 20/30-17/30

=3/10=1/10

3) 8/9:2/5-25/36

=8/9 nhân 5/2 -25/36

=20/9-25/36

=80/36-25/36

=55/36

a) 16 = 2⁴

42 = 2.3.7

ƯCLN(16; 42) = 2

ƯC(16; 42) = Ư(2) = {1; 2}

b) 16 = 2⁴

42 = 2.3.7

86 = 2.43

ƯCLN(16; 42; 86) = 2

ƯC(16; 42; 86) = Ư(2) = {1; 2}

c) 25 = 5²

75 = 3.5²

ƯCLN(25; 75) = 5² = 25

ƯC(25; 75) = Ư(25) = {1; 5; 25}

d) 25 = 5²

55 = 5.11

75 = 3.5²

ƯCLN(25; 55; 75) = 5

ƯC(25; 55; 75) = Ư(5) = {1; 5}

\(a,x+\dfrac{2}{5}=\dfrac{1}{2}\)

\(x=\dfrac{1}{2}-\dfrac{2}{5}\)

\(x=\dfrac{5}{10}-\dfrac{4}{10}\)

\(\Rightarrow x=....\)

\(a,x+\dfrac{2}{5}=\dfrac{1}{2}\\ \Rightarrow x=\dfrac{1}{2}-\dfrac{2}{5}=\dfrac{5-4}{10}=\dfrac{1}{10}\)

\(b,x-\dfrac{2}{5}=\dfrac{1}{7}\\ \Rightarrow x=\dfrac{1}{7}+\dfrac{2}{5}=\dfrac{5+14}{35}=\dfrac{19}{35}\)

\(c,x\cdot\dfrac{3}{4}=\dfrac{9}{20}\\ \Rightarrow x=\dfrac{9}{20}:\dfrac{3}{4}=\dfrac{9}{20}\cdot\dfrac{4}{3}=\dfrac{3\cdot1}{5\cdot1}=\dfrac{3}{5}\)

\(d,x:\dfrac{1}{7}=14\\ \Rightarrow x=14\cdot\dfrac{1}{7}=\dfrac{14}{7}=2\)

\(e,\dfrac{2}{3}-x=\dfrac{1}{5}\\ \Rightarrow x=\dfrac{2}{3}-\dfrac{1}{5}=\dfrac{10-3}{15}=\dfrac{7}{15}\)

\(f,\dfrac{4}{15}:x=\dfrac{12}{25}\\ \Rightarrow x=\dfrac{4}{15}:\dfrac{12}{25}=\dfrac{4}{15}\cdot\dfrac{25}{12}=\dfrac{1\cdot5}{3\cdot3}=\dfrac{5}{9}\)

a, \(x+\dfrac{2}{5}=\dfrac{1}{2}\\ \Rightarrow x=\dfrac{1}{2}-\dfrac{2}{5}\\ \Rightarrow x=\dfrac{5}{10}-\dfrac{4}{10}\\ \Rightarrow x=\dfrac{1}{10}\)

b) \(x-\dfrac{2}{5}=\dfrac{1}{7}\\ \Rightarrow x=\dfrac{1}{7}+\dfrac{2}{5}\\ \Rightarrow x=\dfrac{5}{35}+\dfrac{14}{35}\\ \Rightarrow x=\dfrac{19}{35}\)

c) \(x\times\dfrac{3}{4}=\dfrac{9}{20}\\ \Rightarrow x=\dfrac{9}{20}:\dfrac{3}{4}\\ \Rightarrow x=\dfrac{9}{20}\times\dfrac{4}{3}\\ \Rightarrow x=\dfrac{36}{60}\\ \Rightarrow x=\dfrac{3}{5}\)