4091=4000+90+1

4091=4000+90+1

4091 = 4000 + 90 + 1

a. =[(-4)(-25)].3=100.3=300

b. =[(-8).125][5.2]=-1000.10=-10000

c. =[25.(-4)][(-5).20]=-100(-100)=10000

bủh

có ai giúp mình với 

alooooooooooooooooooo

315+[125-x]=435

125-x=435-315

125-x=120

x=125-120

x=5 

\(315+\left(125-x\right)=435\)

\(125-x=435-315\)

\(125-x=120\)

\(x=125-120\)

\(x=5\)

315 + [ 125-x ]  = 435

            125-x    = 435 - 315
            125-x    = 120

                   x    = 125-120

                   x    =  5

Bài làm :

\(5.5^n=125\)

\(5^{1+n}=5^3\)

\(\Rightarrow1+n=3\)

\(\Rightarrow n=3-1\)

\(\Rightarrow n=2\)

Vậy n = 2 .

Học tốt

Bg

5.5ⁿ = 125

5ⁿ    = 125 : 5

5ⁿ    = 25

5ⁿ    = 5² 

n = 2

Vậy n = 2

\(5.5^n=125\)

\(5^2=125:5\)

\(5^n=25\)

\(5^n=5^2\)

\(n=2\)

vậy \(n=2\)

mn ơi giúp mìnhhhhhh

C =[125.(73-75)]:(-25)2

=125.(-2):(-25).2

=-250:(-50)

=5

E=125.9.(-4).(-8).25.7

=125.(-8).25.(-4).7.9

=-1000.(-100).63

=6300000

C = ( 125 . 73 - 125 . 75 ) : ( -50)

C = 125 .( -2 ) : (-50)

C = -250 : -50

C =  50

G = ( -3 )²+( -5)³: l -5 l

G = 9 + ( -125) : 5

G = 9 + ( -25 )

G= ( -16 )

E = 125 .9.*( -4 ) . ( -8) .25.7

E = 25.5 .( -4 ) .9 .2. ( -4 ) .25 .7

E =( -100 ).10.( -100).63

E = 10000.630

E = 630000

**** mha

\(\Leftrightarrow3x-125=1\)

hay x=42