1: \(=75\left(27+25-2\right)=75\cdot50=3750\)

2: \(=15\left(23+37\right)+55=15\cdot60+55=955\)

3: \(=36\cdot14+36\cdot17+36\cdot69\)

\(=36\cdot100=3600\)

4: \(=200\cdot\left(32+68\right)=200\cdot100=20000\)

a,  x - 1 2 = 36

ó  x - 1 2 = 6 2

ó x – 1 = 6

ó x = 7

Vậy x = 7

b,  7 x - 11 3 = 2 5 . 5 2 + 200

=> 7 x - 11 3 = 800 + 200

=> 7 x - 11 3 = 1000

=> 7 x - 11 3 = 10 3

=> 7x – 11 = 10

=> 7x = 21

=> x = 3

Vậy x = 3

c,  x 11 = x

=> x 11 - x = 0

=> x ( x 10 - 1 ) = 0

=>

d,  x 2 = 2 3 + 3 2 + 4 3

=>  x 2 = 81

=> x = 9

e,  2 x 3 3 2 = 48

=>  2 x 3 9 = 48

=>  2 x 3 = 48 . 9

=>  x 3 = 216

=>  x 3 = 6 3

=> x = 6

f,  2 x + 1 3 = 125

=> 2 x + 1 3 = 5 3

=> 2x + 1 = 5

=> 2x = 4

=> x = 2

2: \(x^2-2xy+y^2-2x+2y\)

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

=(x-y)(x-y-2)

3: \(3x^2-2x-5\)

\(=3x^2-5x+3x-5\)

=x(3x-5)+(3x-5)

=(3x-5)(x+1)

4: \(16-x^2+4xy-4y^2\)

\(=16-\left(x^2-4xy+4y^2\right)\)

\(=4^2-\left(x-2y\right)^2\)

=(4-x+2y)(4+x-2y)

5: \(x^2-2x+1-y^2\)

\(=\left(x-1\right)^2-y^2\)

=(x-1-y)(x-1+y)

6: \(x^2+8x+15\)

\(=x^2+3x+5x+15\)

=x(x+3)+5(x+3)

=(x+3)(x+5)

7: \(\left(x^2+6x+8\right)\left(x^2+14x+48\right)-9\)

=(x+2)(x+4)(x+6)(x+8)-9

\(=\left(x^2+10x+16\right)\left(x^2+10x+24\right)-9\)

\(=\left(x^2+10x\right)^2+40\left(x^2+10x\right)+384-9\)

\(=\left(x^2+10x\right)^2+15\left(x^2+10x\right)+25\left(x^2+10x\right)+375\)

\(=\left(x^2+10x+25\right)\left(x^2+10x+15\right)=\left(x+5\right)^2\cdot\left(x^2+10x+15\right)\)

8: \(\left(x^2-8x+15\right)\left(x^2-16x+60\right)-24x^2\)

\(=\left(x-3\right)\left(x-5\right)\left(x-6\right)\left(x-10\right)-24x^2\)

\(=\left(x^2-13x+30\right)\left(x^2-11x+30\right)-24x^2\)

\(=\left(x^2+30\right)^2-24x\left(x^2+30\right)+143x^2-24x^2\)

\(=\left(x^2+30\right)^2-24x\left(x^2+30\right)+119x^2\)

\(=\left(x^2-7x+30\right)\left(x^2-17x+30\right)\)

\(=\left(x^2-7x+30\right)\left(x-2\right)\left(x-15\right)\)

Đáp án cần chọn là: B

x–43=(35−x)−48

x–43=35–x−48

x+x=35–48+43

2x=30

x=15

2x+69.2=69.4

2x+138=276

2x = 276-138

2x = 138

x = 138:2

x = 69

2x-12-x = 0

<=> 2x-x-12 =0

(2x-x)-12=0

=> x-12=0

x = 0+12

x  =12

(x-7)(2x-8)=0

\(\Rightarrow\hept{\begin{cases}x-7=0\\2x-8=0\end{cases}}\Rightarrow\hept{\begin{cases}x=7\\x=4\end{cases}}\)

Vậy ...

a, 2X+69.2=69.4

2X+138=276

2X=276-138=138

X=138:2=69

b,2X-12-x=0 

2X-X=12-0

x=12

mik chi biet vay thoi con cau cuoi mik chiu

a) -152 - (3x + 1) = (-2).(-3)³

-152 - 3x - 1 = (-2).(-27)

-3x - 153 = 54

-3x = 54 + 153

-3x = 207

x = -69

b) x - 43 = (35 - x) - 48

x - 43 = 35 - x - 48

x - 43= -x - 13

x = -x - 13 + 43

x = 30 + x

x + x = 30

2x = 30

x = 15