A.\(\left(x-15\right).15=0\)

\(x-15=0:15\)

\(x-15=0\)

\(x=15+0\)

\(x=15\)

B.\(32\left(x-10\right)=32\)

\(x-10=32:32\)

\(x-10=1\)

\(x=10+1\)

\(x=11\)

`a) `

`(x-15)xx15=0`

`<=> x-15 = 0 : 15`

`<=> x-15 = 0`

`<=> x = 0 + 15`

`<=> x =15`

`b)`

`32.(x-10)=32`

`<=> x - 10 = 32:32`

`<=>x-10=1`

`<=> x = 1+10`

`<=> x =11`

`c)`

`(x-5).(x-7)=0`

`<=>` \(\left[ \begin{array}{l}x-5 = 0\\x-7=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=5\\x=7\end{array} \right.\) 

`d)`

`(x-35)xx35=35`

`<=> x - 35 = 35:35`

`<=> x - 35 = 1`

`<=> x = 1+35`

`<=> x = 36`

a)(x-15)=0     

x=15

Vậy c=15

b)(x-10)=1

x=11

Vậy x=11

c)(x-5)(x-7)=0

x=5 hoặc x=7

Vậy \(x\in\left\{5;7\right\}\)

\(a.\)\(\frac{13x-16}{15}+\frac{x-32}{35}< \frac{x-6}{21}\)\(MC:105\)

\(\Leftrightarrow\frac{7\left(13x-16\right)}{105}+\frac{3\left(x-2\right)}{105}< \frac{5\left(x-6\right)}{105}\)

\(\text{Khử mẫu ta dc pt tương đương vs pt:}\)

\(\Leftrightarrow7\left(13x-16\right)+3\left(x-2\right)< 5\left(x-6\right)\)

\(\Leftrightarrow91x-112+3x-6< 5x-30\)

\(\Leftrightarrow94x-118< 5x-30\)

\(\Leftrightarrow94x-5x< 118-30\)

\(\Leftrightarrow89x< 88\)

\(\Leftrightarrow x< \frac{88}{89}\)

.\(b.\)\(\frac{5x+12}{14}+\frac{11x+28}{3}>\frac{4x+9}{17}\)\(MC:714\)

\(\text{Khi khử mẫu pt ta dc pt tương đương}:\):

\(\Leftrightarrow51\left(5x+12\right)+238\left(11x+28\right)>42\left(4x+9\right)\)

\(\Leftrightarrow255x+612+2618x+6664>168x+378\)

\(\Leftrightarrow2873x+7276>168x+378\)

\(\Leftrightarrow2873x-168x>-7276+378\)

\(\Leftrightarrow2705x>-6898\)

\(\Leftrightarrow x>-\frac{6898}{2705}\)

a,(5.9.x-25):12=0

  (45.x-25):12=0

 (45.x-25)     =0x12

(45.x-25)=0

45.x=0+25

45.x=25

x=25:45

x=5/9

b,30.(x-28)=120

        (x-28)=120:30

        (x-28)=4

         x=4+28

        x=32

c'84-4.(2.x+1)=48

       4.(2.x+1)=84-48

        4.(2.x+1)=36

             (2.x+1)=36:4

            (2.x+1)=9

           2.x=9-1

            2.x=8

            x=8:2

             x=4

d,[(x+32)-15].2=60

  [(x+32)-15]=60:2

[(x+32)-15]=30

 (x+32)=30+15

(x+32)=45

x=45-32

x=13

a,

(5.9.x-15):12=0

45x-15=0

45x=0+15=15

x=45:15

x=3

b, 

30(x-28)=120

x-28=120:30=4

x=4+28

x=32

c,

84-4(2.x+1)=48

4(2.x+1)=84-48=36

2x+1=36:4=9

2x=9-1=8

x=8:2

x=4

d,

[(x+32)-15].2=60

(x+32)-15=60:2=30

x+32=30+15=45

x=45-32

x=13

Bài 6:

a)(x-15).15=0

⇔x-15=0

⇔x=15

b)32(x-10)=32

⇔x-10=1

⇔x=11

c)(x-5)(x-7)=0

⇔x-5=0 hay x-7=0

⇔x=5 hay x=7

d)(x-35)35=35

⇔x-35=1

⇔x=36

bn lớp mấy vậy

a, x=15
b, x=11
c, x=7
d, x=36

Bài 6:

a)(x-15).15=0

⇔x-15=0

⇔x=15

b)32(x-10)=32

⇔x-10=1

⇔x=11

c)(x-5)(x-7)=0

⇔x-5=0 hay x-7=0

⇔x=5 hay x=7

d)(x-35)35=35

⇔x-35=1

⇔x=36

a, x = 15
b, x = 11
c, x = 7 hoặc x = 5
d, x = 36