Cách 1: a. (125.63):5=7875:5
                                  =1575
Cách 2: a. (125.63):5=(125:5).63
                                   =25.63
                                   =1575
(Bạn sửa dấu " . " thành dấu nhân giúp mik nhé)

Cách 1: a. (125.63):5=7875:5
                                  =1575
Cách 2: a. (125.63):5=(125:5).63
                                   =25.63
                                   =1575
(Bạn sửa dấu " . " thành dấu nhân giúp mik nhé)

( 1+3+5+7+…+2003+2005) x (125 125 x 127 – 127 127 x 125)

= ( 1+3+5+7+…+2003+2005) x (125 x 1001 x 127 – 127 x 1001x 125)

=  ( 1+3+5+7+…+2003+2005) x                   0  =    0

\(\left(x^{54}\right)^2=x^{54.2}=x^{108}\\ Mà:\left(x^{54}\right)^2=5^{108}\Leftrightarrow x^{108}=5^{108}=\left(-5\right)^{108}\\ Vậy:x=5.hoặc.x=-5\\ ---\\ \left(5^x\right)^2=125^3:5^2\\ \Leftrightarrow5^{2x}=\left(5^3\right)^3:5^2=5^9:5^2=5^7\\ Vậy:2x=7\\ Vậy:x=\dfrac{7}{2}\)

\(\left(x^{54}\right)^2=5^{108}\\ \Rightarrow x^{108}=5^{108}\)

\(\Rightarrow x=5.\)

\(\left(5^x\right)^2=125^3:5^2\\ \Rightarrow\left(5^x\right)^2=\left(5^3\right)^3:5^2\\ \Rightarrow\left(5^x\right)^2=5^9:5^2\\ \Rightarrow\left(5^x\right)^2=5^7\\ \Rightarrow x.2=5\\ \Rightarrow x=2,5\)

Cho mk sửa : 

\(\Rightarrow x.2=7\\ \Rightarrow x=3,5.\)

(45/5+5/5)×x=125×4

10×x=500

X=500÷10

X=50

=500000-100000

=400000

b) 25 x 20 x 125 x 8 - 8 x 20 x 5 x 125

= 25 x 20 x 25 x 5 x 8 - 8 x 20 x 5 x 5 x 25

= 25 x 20 x 25 x 40 - 8 x 10 x 25 x 25

= 500 x 1000 - 80 x 625

= 500 000 - 50000

= 450000

 25 x 20 x 125 x 8 - 8 x 20 x 5 x 125

= 25 x 20 x 25 x 5 x 8 - 8 x 20 x 5 x 5 x 25

= 25 x 20 x 25 x 40 - 8 x 20 x 25 x 25

= 500 x 1000 - 160 x 625

= 500 000 - 100000

= 400000

(5^2.x-5^x+1)/5=125

25.x-5^x+1=625

4 × 125 × 25 × 8

= (4 × 25) × (125 × 8)

= 100 × 1000

= 100 000

2 × 8 × 50 × 25 × 125

= (2 × 50) × (8 × 125) × 25

= 100 × 1000 × 125

= 12 500 000

2 × 3 × 4 × 5 × 50 × 25

= (2 × 50) × (4 × 25) × (3 × 5)

= 100 × 100 × 15

= 150 000

25 × 20 × 125 × 8 - 8 × 20 × 5 × 125

= 8 × 125 × 20 × (25 - 5)

= 1000 × 20 × 20

= 400 000

- (25 x 4) x (125 x8)=100 x 1000 =100000

- (50 x 2) x (8 x 125) x 25=100 x 1000 x 25 =2500000

- (2 x 50 ) x (4 x 25) x (3 x5)=100 x 100 x 15=150000

- 25 x 20 x125 x 8 - 5

= (20 x 5) x (125 x 8) -25=100 x 1000 -5 =100000 - 5 =99995

4 *125*25*8

=4*25*125*8

=100*1000

=100000

2*8*50*25*125

=2*50*8*125*25

=100*1000*25

=2500000

2*3*4*5*50*25

=2*50*4*25*3*5

=100*100*15

=150000

25*20*125*8-8*20*5*125

=25*4*5*125*8-8*125*20*5

=100*1000*5-1000*100

=500000-100000

=400000

=

125-125.(x-5)=100

125.(x-5)=125-100

125.(x-5)=25

x-5=25:125

x-5=1/5

x=1/5+5

x=26/5

125-125.(x-5)=100

x=100+5

x=100

thử lại

125-125.(105-5)=100=>

1.100=100

nhầm, x=105 =))

\(5^x\cdot5^3=125\)

\(\Rightarrow5^x\cdot5^3=5^3\)

\(\Rightarrow5^{x+3}=5^3\)

\(\Rightarrow x+3=3\)

\(\Rightarrow x=3-3\)

\(\Rightarrow x=0\)

Vậy: x = 0