a) (x + 5)² - x² = 45

<=> (x + 5 - x)(x + 5 + x) = 45

<=> 5(2x + 5) = 45

<=>> 2x + 5 = 9

<=> 2x = 4

<=> x = 2

Vậy S = {2}

b) (2x + 1)(1 - 2x) + (2x - 1)² = 22

<=> (2x - 1)(-2x - 1 + 2x - 1) = 22

<=> -2(2x - 1) = 22

<=> 2x - 1 = -11

<=> 2x = -10

<=> x = -5

c) (3x - 5)² - ((3x + 1)² = -3

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

<=> -6(6x - 4) = -3

<=> 6x - 4 = 1/2

<=> 6x = 9/2

<=> x = 3/4

a,(x+5)²-x²=45

x²+10x+25-x²=45

10x+25=45

10x=20=> x=2

b,(2x+1)(1-2x)+(2x-1)²=22

(1+2x)(1-2x)+4x²-4x+1=22

1-4x²+4x²-4x+1=22

2-4x=22

4x=-20

x=-5

a,(x-5)^2=25

(x-5)^2=5^2

=>x-5=5

x=5+5=10

Vậy x=10

b,(2x+1)^2=25

(2x+1)^2=5^2

=>2x+1=5

2x=6

x=6:2

x=3

Vậy x=3

c,(3x-2^4).7^3=2.7^4

3x-2^4=2.7^4:7^3=14

3x=16+14=30

x=30:3

x=10

Vậy x=10

d,2.3^x+3^2+x=891

\(5^{2x-3}-25^2=5^{2.3}\)

\(5^{2x-3}-\left(5^2\right)^2=5^6\)

\(5^{2x-3}-5^4=5^6\)

-> 2x - 3 - 4 = 6

2x - 3 = 4 + 6

2x - 3 = 10

2x = 10 + 3

2x = 13

x = \(\frac{13}{2}\)

\(\frac{13}{2}=6,5\)nha

\(5^{2x}-3-25^2=3.5^2\)

\(25^x-25^2=3\left(5^2+1\right)\)

\(\Leftrightarrow25^x=78\)

Vậy........

a) 3⁸ : 3⁴ + 2² x 2³ =  113

b) 3 x 4² - 2 . 3 = 42

c) 4⁶ . 3⁴ . 9⁵ : 6¹² = 9

d) 21² . 14 . 125 : 35³ . 6 = 108

e) 45³ . 20⁴ .18² : 180⁵ = 25

#BạcHà#

bn ơi ghi cả cách làm nữa bn 

ai lm lun cách làm mk sẽ k cho 2 k lun

đợi xíu nhé tí nữ mình trả lời cho bh mình đanbg bận

a)

\(\text{( 25 – 2x )³ : 5 – 3^2 = 4^2}\)

\(\text{( 25 – 2x )³ : 5 – 9 = 16}\)

\(\text{( 25 – 2x )³ : 5 = 16 + 9}\)

\(\text{( 25 – 2x )³ : 5 = 25}\)

\(\text{( 25 – 2x )³ = 25 . 5}\)

\(\text{( 25 – 2x )³ = 125}\)

\(\text{( 25 – 2x )³ = 5³}\)

\(\text{25 – 2x = 5}\)

\(\text{2x = 25 – 5}\)

\(\text{2x = 20}\)

\(\text{x = 10}\)

\(\text{________________________________________}\)

b)

\(\text{2.3^x = 10.3^12 + 8.27^4}\)

\(\text{2.3^x = 10.3^12 + 8.(3^3)^4}\)

\(\text{2.3^x = 3^12 . (10+8)}\)

\(\text{2.3^x = 3^12 . 18}\)

\(\text{3^x = 3^12 . 18:2}\)

\(\text{3^x = 3^12 . 9}\)

\(\text{3^x = 3^12 . 3^2}\)

\(\text{3^x = 3^14}\)

\(\text{=> x=14}\)

\(9^2\cdot3^5=3^4\cdot3^5=3^9\\ 9^2\cdot27\cdot3^5=3^4\cdot3^3\cdot3^5=3^{12}\)

\(9^2\cdot3^5=3^4\cdot3^5=3^9\)

\(9^2\cdot27\cdot3^5=3^4\cdot3^3\cdot3^5=3^{12}\)

a, 3⁸ : 3⁴ +2² *2³

=3⁴ + 2⁵

=81+32

=113

b, 3 * 4² - 2 * 3

=3 * 16 -6

=48 - 6

=42