a) \(\left(x-2\right)^2-11=25\)

\(\left(x-2\right)^2=25+11\)

\(\left(x-2\right)^2=36\)

\(\left(x-2\right)^2=6^2\)

\(\Rightarrow x-2=6\)

\(\Rightarrow x=8\)

vậy \(x=8\)

những câu khác làm tương tự

học vui truong the dat 

a, \(\left(x-2\right)^2-11=25\)

\(\Rightarrow\left(x-2\right)^2=25+11\)

\(\Rightarrow\left(x-2\right)^2=36\)

\(\Rightarrow\left(x-2\right)^2=6^2=\left(-6\right)^2\)

\(\Rightarrow x-2=6\)hoặc \(x-2=-6\)

\(\Rightarrow x\in\left\{8;-4\right\}\)

a) (x-2)²-11=25

=>(x-2)²=25+11=36

=>x-2=6

=>x=6+2=8

b)=> 3.(x-4)-12=6 (Khi x-4 lớn hơn hoặc bằng 0) 

hoặc 3.(4-x)-12=6 (Khi x-4 nhỏ hơn 0)

=> 3x-12-12=6 

hoặc 12-3x-12=6

=>3x=6+12+12=30

hoặc -3x=6

=>x=10 hoặc =2

c)7x³-12=44

=>7x³=44+12=56

=>x³=8

=>x=2

d)(x-7)(x+2)=0

=> x-7=0 hoặc x+2=0

=>x=7 hoặc x=-2

\(\dfrac{7}{16}+\dfrac{-1}{8}+\dfrac{9}{32}=\dfrac{14}{32}-\dfrac{4}{32}+\dfrac{9}{32}=\dfrac{19}{32}\)

\(\dfrac{5}{4}-\dfrac{25}{30}\times\dfrac{37}{44}+\dfrac{-25}{30}\times\dfrac{13}{44}+\dfrac{-25}{30}\times\dfrac{-6}{44}\)

\(=-\dfrac{25}{30}\times\left(\dfrac{5}{4}+\dfrac{37}{44}+\dfrac{13}{44}-\dfrac{6}{44}\right)\)

\(=-\dfrac{25}{30}\times\left(\dfrac{55}{44}+\dfrac{37}{44}+\dfrac{13}{44}-\dfrac{6}{44}\right)\)

\(=-\dfrac{25}{30}\times\dfrac{99}{44}\)

\(=-\dfrac{5}{6}\times\dfrac{9}{4}\)

\(=-\dfrac{15}{8}\)

\(\left(\dfrac{7}{16}+\dfrac{-1}{8}+\dfrac{9}{32}\right):\dfrac{5}{4}\)

\(=\left(\dfrac{14}{32}+\dfrac{-4}{32}+\dfrac{9}{32}\right):\dfrac{5}{4}\)

\(=\dfrac{19}{32}:\dfrac{5}{4}\)

\(=\dfrac{19}{32}.\dfrac{4}{5}=\dfrac{19.4}{32.5}=\dfrac{19}{40}\)

\(\dfrac{-25}{30}.\dfrac{37}{44}+\dfrac{-25}{30}.\dfrac{13}{44}+\dfrac{-25}{30}.\dfrac{-6}{44}\)

\(=\dfrac{-25}{30}.\left(\dfrac{37}{44}+\dfrac{13}{44}+\dfrac{-6}{44}\right)\)

\(=\dfrac{-25}{30}.\dfrac{44}{44}=\dfrac{-5}{6}.1=-\dfrac{5}{6}\)

Bài 3: 

a: \(x\in\left\{-5;-4;-3;-2;-1\right\}\)

b: \(x\in\left\{-3;-2;-1;0;1;2;3;4;5;6\right\}\)

a: 

b: 

a) >

b) =

c) <

~~tk mk nha các bn~~^^

âm điểm quớ trời nè T_T

Đáp án:

7h37p

8h50p

9h45p

6h5p

b12: 

16h3p

2h53p

16 ngày 12h

3p4s

1: =-2/9(15/17+2/17)=-2/9

2: \(=\dfrac{-6}{3}+\dfrac{-21}{90}\)

=-2-7/30=-67/30

3: \(=\dfrac{3}{4}\cdot\dfrac{7}{5}+\dfrac{9}{7}\cdot\dfrac{3}{2}\)

=21/20+27/14=417/140

4: =-25/13(5/19+14/19)=-25/13

5: =-7/5-45/21=-7/5-15/7=-124/35

1: =-2/9(15/17+2/17)=-2/9

2: =34⋅75+97⋅32=34⋅75+97⋅32

=21/20+27/14=417/140

4: =-25/13(5/19+14/19)=-25/13

5: =-7/5-45/21=-7/5-15/7=-124/35

1: 243^5=(3^5)^5=3^25

3*27^8=3*(3^3)^8=3^25

=>243^5=3*27^8

6: 125^5=(5^3)^5=5^15

25^7=(5^2)^7=5^14

=>125^5>25^7(15>14)

5: 78^12-78^11=78^11(78-1)=78^11*77

78^11-78^10=78^10*77

mà 11>10

nên 78^12-78^11>78^11-78^10

` @ \color{Red}{m}`

` \color{lightblue}{Answer}`  

`6/25 -17/13 + 44/25 + 4/13`

`= (6/25 +44/25) +(-17/13 + 4/13)`

`= 50/25 + (-13/13)`

`= 2 + (-1)`

`=1`

6/25 - 17/13 + 44 / 25 + 4/13

= 6/25 + 44/25 - 17/13 + 4/13

= 50/25 - 13/13

= 2 - 1

= 1