a) 2²(6x - 3²) - 3 = 33

4(6x - 9) = 33 + 3

4(6x - 9) = 36

6x - 9 = 36 : 4

6x - 9 = 9

6x = 9 + 9

6x = 18

x = 18 : 6

x = 3

b) 4(x + 2) = 3(x + 1) + 17

4x + 8 = 3x + 3 + 17

4x - 3x = 3 + 17 - 8

x = 12

x=17 nhé

mk kô bt đánh ps đâuu à

a) x+30%x=-1.31

=> 100%x+30%x=-1.31

=>x.(100%+30%)=-1.31

=>x.13/10=-1.31=-1.31:13/10=-131/130

b) (x-1/2):1/3+5/7=9+5/7

=>(x-1/2).3+5/7=68/7

=>(x-1/2).3=68/7-5/7=9

=>x-1/2=9:3=3

=>x=3+1/2=3 1/2( hỗn số)

c) 1/2x-3/4=14/9.3/7

=>1/2x-3/4=2/3

=>1/2x=2/3+3/4=17/12

x=17/12:1/2=17/12.2=17/6

d) - 5/6 -x = 7/12+ -1/3

=>- 5/6 -x = 7/12+ -4/12=1/4

=> x = -5/6 -1/4=-13/12

e) x + 3/-15 = 1/3

=> x= 1/3 - -3/15 =1/3+3/15

=> x=5/15 + 3/15=8/15

f) (4,5 -2 x). (-1 4/7)=11/14

=> 4,5 -2x=11/14 : -3/7=11/14. -7/3=-11/6

=>-2x=-11/6-9/2= -11/6 -27/6 =-19/3

=>x= -19/3: -2x=19/6

Chúc bn thi HKII tốt!!!

ban hoc truong nao vay ? de cua ban giong cua minh lam

bạn học trường j mà giống đề bài mình zay

=3/7*4/4+3/7*3/2 

= 3/7*(4/4+3/2)

........... 

\(\frac{3}{4}\times\frac{4}{7}+\frac{3}{7}\times\frac{3}{2}\)

\(=\frac{3}{7}+\frac{9}{14}=\frac{15}{14}\)

\(X+\frac{31}{2}+X=24\frac{1}{4}\)

\(\Rightarrow2x+\frac{31}{2}=24\frac{1}{4}\)

\(\Rightarrow2x=24\frac{1}{4}-\frac{31}{2}\)

\(\Rightarrow2x=\frac{35}{4}\)

\(\Rightarrow x=\frac{35}{4}:2=\frac{35}{8}\)

H(x) = \(2\left(x^2+4\right)-\dfrac{3}{2}\left(4+2x^2\right)=2x^2+8-6-3x^2\)

\(=-x^2+2\)

H(-5) = -[(-5)²] +2 = -25+2 = -23

a) Ta có: \(H\left(x\right)=2\left(x^2+4\right)-\dfrac{3}{2}\left(4+2x^2\right)\)

\(=2x^2+8-6-3x^2\)

\(=2-x^2\)

                                Trả lời :

           \(x+3\frac{1}{4}+x=24\frac{1}{4}\)

           \(x+\frac{13}{4}+x=\frac{97}{4}\)

          \(x\text{ x 2 }+\frac{13}{4}=\frac{97}{4}\)

         \(x\text{ x 2 }=\frac{97}{4}-\frac{13}{4}\)

         \(x\text{ x 2 }=\frac{84}{4}=21\)

        \(x=21:2\)

        \(x=10,5\)

\(x+3\frac{1}{4}+x=24\frac{1}{4}\)

\(\Rightarrow2x+\frac{13}{4}=\frac{97}{4}\)

\(\Rightarrow2x=21\)

\(\Rightarrow x=\frac{21}{2}\)

\(x+3\frac{1}{4}+x=24\frac{1}{4}\)

\(2\times x+\frac{13}{4}=\frac{97}{4}\)

\(2\times x=\frac{97}{4}-\frac{13}{4}\)

\(2\times x=21\)

\(x=21:2\)

\(x=10,5\)

a) 2/3x +1/2 = 1/10

     => 2/3x = 1/10 - 1/2

          2/3x = -2/5

         => x = -2/5 : 2/3

             x = -3/5

b) (4,5 - 2x) : 3/4 = \(1\frac{1}{3}=\frac{4}{3}\)

=> 4,5 - 2x = 4/3 x 3/4

    4,5 - 2x = 1

        -2x = 4,5 - 1

        -2x = 3,5

        => x = 3,5 : (-2)

             x = - 1,75

c) x/4 = 5/20

    => x = 5/20 x 4

       x = 1

d) ?????

2/3x+1/2=1/10

<=>2/3x=1/10-1/2

<=>2/3x=-2/10

=>x=-2/10 chia 2/3=-3/10

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