a: =25(15+45*3)

=25*150

=3750

b: \(=-10\left(25+75-50\right)=-10\cdot50=-500\)

c: =>3^x-2=27

=>x-2=3

=>x=5

d: =>2x-5=-4

=>2x=1

=>x=1/2

e: =>2(x-1)^2=32

=>(x-1)^2=16

=>x-1=4 hoặc x-1=-4

=>x=-3 hoặc x=5

f:  =>25(x+3)=75

=>x+3=3

=>x=0

`75 xx 1/x + 25 xx 1/x = 10`

`1/x xx (75+25) = 10`

`=> 1/x xx 100 = 10`

`=> 1/x = 10/100`

`=> 1/x = 1/10`

`=> x = 10`.

=>100:x=10

hay x=10

`x : 75 : x + 25 : x = 10`

`x : 100 = 10`

`x = 10xx100`

`x = 1000`

3 . [ 25 - ( x - 10 ) ] - 75 = 0

3 . [ 25 - ( x - 10 ) ] = 75

25 - ( x - 10 ) = 75 : 3

25 - ( x - 10 ) = 25

x - 10 = 25 - 25

x - 10 = 0

x = 0 + 10

x = 10

Vậy x = 10

\(3\cdot\left[25-\left(x-10\right)\right]-75=0\)

\(3\cdot\left[25-\left(x-10\right)\right]=0+75\)

\(3\cdot\left[25-\left(x-10\right)\right]=75\)

\(25-\left(x-10\right)=75:3\)

\(25-\left(x-10\right)=25\)

\(x-10=25-25\)

\(x-10=0\)

\(x=0+10\)

\(x=10\)

3 . [25 - (x - 10)] - 75 = 0

=> 3 . [25 - (x - 10)] = 0 + 75

=> 3 . [25 - (x - 10)] = 75

=> 25 - (x - 10) = 75 : 3

=> 25 - (x - 10) = 25

=> x - 10 = 25 - 25

=> x - 10 = 0

=> x = 0 + 10

=> x = 10

Vậy x = 10

\(\dfrac{1}{x}\times\left(75+25\right)=10\)

\(\dfrac{1}{x}=\dfrac{10}{75+15}=\dfrac{1}{10}\)

=> x = 10

`=>100:x=10`

hay `x=10`

 x : 75 : x + 25 : X = 10

 x :(75+25)            =10

 x  :  100                =10

 x                           =10x100

 x                           =1000

10 . 20 - 100 . 75 + 10 . 80 + 100 . 25

= 10 . ( 20 + 80 ) - 100 . ( 75 + 25 )

= 10 . 100 - 100 . 100 

= 1000 - 10000

= - 9000

10 x 20 -100 x 75 + 10 x 80 - 100 x  25 

10. 10. 2 - 100. 75 + 10. 10. 8 - 100 .25

100.2 -100.75 +100.8 - 100.25

200 - 7500 + 800 - 2500

vô lý

10x20-100x75+10x80-100x25

200-7500+800-2500

-9000

`|-25/10|×0,2+75%:(5/2)^2`

`=25/10×1/5+3/4:25/4`

`=5/10+3/4×4/25`

`=1/2+3/25`

`=25/50+6/50`

`=31/50`

a) ( - 78 ) . ( 1 + 187 ) + 187 . 78

= ( - 78 ) + ( - 78 ) . 187 + 187 . 78

= ( - 78 ) + 187 . [ ( - 78 ) + 78 ]

= ( - 78 ) + 187 . 0

= ( - 78 ) + 0

= ( - 78 )

b) ( - 39 ) . 15 - 36 . 39 - 49 . ( - 39 )

= ( - 39 ) . 15 + 36 . ( - 39 ) - 49 . ( - 39 )

= ( - 39 ) . ( 15 + 36 - 49 )

= ( - 39 ) . 2

= - 78

a) (-78).(1+187) + 187.78 = -78 - 78.187 +187.78 = -78

b) (-39).15 - 36.39 - 49.(-39)

= -39.15 - 36.39 + 49.39

=39.(-15-36+49)

= 39.(-2)

= - 78

Tích mk nha !!!!~~

a) ( -78 ) . ( 1+187 ) + 187 . 78

= 78 . -(1+187) +187 . 78

=78 . -188 + 187 . 78

= 78 . ( -188 + 187 )

=78 . -1 = -78

b) ( -39 ) .15 -36 . 39 -49.(-39)

=(-39).15+36.(-39) - 49 .(-39)

=-39. ( 15+36-49)

=-39 . 2

=-78

học tốt ~~~