a)

b)

c) 

a, \(2x+3⋮2x-1\)

\(2x-1+4⋮2x-1\)

\(4⋮2x+1\)hay \(2x+1\inƯ\left(4\right)=\left\{1;2;4\right\}\)

c, \(\left(x+5\right)\left(y-3\right)=15\Leftrightarrow x+5;y-3\inƯ\left(15\right)=\left\{1;3;5;15\right\}\)

a) x.5-3=x+(-11)

5x-3-x+11=0

4x+8=0

4x=-8

x=-2

b) x.(-2)+3=-7-x

-2x+3+7+x=0

-x+10=0

-x=-10

x=10

#Hoctot

cảm ơn

Đề:........

<=> 2.|x + 1| = 218 - 64

<=> 2.|x + 1| = 154

<=> |x + 1| = 154 : 2

<=> |x + 1| = 77

=> \(\orbr{\begin{cases}x+1=77\\x+1=-77\end{cases}\Rightarrow\orbr{\begin{cases}x=76\\x=-78\end{cases}}}\)

Vậy x = {76; -78}

218 - 2|x + 1| = 64

         2 |x +1|=218-64

         2 |x +1|=154

            |x +1|=77

=> x= 76 hoặc -78

218 - 2| x + 1 | = 64

=> 2| x + 1 | = 154

=> | x + 1 | = 77

=> x + 1 = 77 hoặc x + 1 = -77

=> x = 76 hoặc x = -78

a) - ( - 32 - 2x ) - ( 4x - 10 ) = - 38 

 32 + 2x - 4x + 10 = - 38 

                      - 2x = - 86

                          x = 43

b) ( x - 16 ) - ( - x - 17 ) - ( 17 - x ) - ( 4x -12 )= -9

                   x - 16 + x + 17 - 17 + x - 4x + 12 = - 9

                                                                  - x = - 5

                                                                    x = 5

a) \(-\left(-32-2x\right)-\left(4x-10\right)=-38\)

\(\Leftrightarrow32+2x-4x+10=42-2x=-38\)

\(\Leftrightarrow-2x=-38-42=-80\Rightarrow x=\left(-80\right)\div\left(-2\right)=40\). Vậy x = 40

b) \(\left(x-16\right)-\left(-x-17\right)-\left(17-x\right)-\left(4x-12\right)=-9\)

\(\Leftrightarrow x-16+x+17-17+x-4x+12=-9\)

\(-x-4=-9\Leftrightarrow-x=-9+4=-5\Leftrightarrow x=5\). Vậy \(x=5\)

\(1.\left(a-b\right)+\left(b-a-c\right)=a-b+b-a-c=-c\)

\(2.\left(a-b\right)-\left(a-b+c\right)=a-b-a+b-c=-c\)

\(3.\left(-a+c-d\right)-\left(c-a+d\right)=-a+c-d-c+a-d=-2d\)\

\(4.\left(b+d\right)+\left(-a+b+d\right)=b+d-a+b+d=-a+2b+2d\)

\(5.\left(a+b+c\right)-\left(a+b-5\right)=a+b+c-a-b+5=c+5\)

\(6.\left(a-b-c\right)-\left(-a-b-c\right)-\left(-a+b-c\right)-\left(c-a-b\right)+\left(-3a-c\right)\)

\(=a-b-c+a+b+c+a-b+c-c+a+b-3a-c\)

\(=\left(a+a+a+a-3a\right)+\left(-b+b-b\right)\)

Xl mình làm lại câu 6

\(\left(a-b-c\right)-\left(-a-b-c\right)-\left(-a+b-c\right)-\left(c-a-b\right)+\left(-3a+c\right)\)

\(=a-b-c+a+b+c+a-b+c-c+a+b-3a+c=a+c\)

a) \(x+\left(-10\right)-\left[87+\left(-41\right)+\left(-20\right)-x\right]\)

\(=x-10-\left(87-41-20-x\right)=x-10-87+41+20+x\)

\(=\left(x-x\right)+\left(20-10\right)-\left(87-41\right)=10-46=-36\)

b) \(a+\left(250-186\right)-\left(270-186\right)=a+250-186-270+186\)

\(=a+\left(250-270\right)+\left(186-186\right)=a-20\)

c) \(b-\left(393+170\right)+\left(93+170\right)=b-393-170+93+170\)

\(=b+\left(170-170\right)-\left(393-93\right)=b-300\)

d) \(-\left(a-b+c\right)-\left(a+b+c\right)=-a+b-c-a-b-c=-2a-2c\)

@Vũ Cao Minh⁀ᶦᵈᵒᶫ Phèn=)

Cảm ơn nhìu lắm =)

\(d)2.169.12-3.68.8-24\)

\(=\left(2.12\right).169-\left(3.8\right).68-24.1\)

\(=24.169-24.69-24.1\)

\(=24.\left(169-68-1\right)\)

\(=24.100\)

\(=2400\)

\(e)2.56.24-3.36.16+4.12.95-6.3.8.5\)

\(=2.24.56-3.16.36+4.12.95-6.8.3.5\)

\(=48.56-48.36+48.95-48.15\)

\(=48.\left(56-36+95-15\right)\)

\(=48.\left(20+80\right)\)

\(=48.100\)

\(=4800\)

d)   2.169.12 - 3.68.8 - 24

= [ 2.12 ] - [ 3 .8 ] - [ 169 . 68 ]

= 24 - 24 - 11492

= 0 - 11492

= 0 + ( - 11492 )

= - 11492