Question

Tìm x :

a) (x - 2)² = 9.16

b) (x - 1)³ = 8

c) 5^3x +2 = 25^x + 3

Answer 1

a) (x - 2)² = 9.16

=> (x - 2)² = 144

=> (x - 2)² = 12²

=> x - 2 = 12

=> x = 12 + 2 = 14

b) (x - 1)³ = 8

=> (x - 1)³ = 2³

=> x - 1 = 2

=> x = 2 + 1 = 3

Answer 2

a)\(\left(x-2\right)^2=9.16\)

\(\Rightarrow\left(x-2\right)^2=144=12^2\)

\(\Rightarrow x-2=12\)

\(\Rightarrow x=12+2=14\)

vậy x =14

b)\(\left(x-1\right)^3=8\)

\(\Rightarrow\left(x-1\right)^3=2^3\)

\(\Rightarrow x-1=2\)

\(\Rightarrow x=2+1=3\)

vậy x=3

Answer 3

c. 5^3x + 2 = 25^x + 3

=> 5^3x + 2 = (5²)^x + 3

=> 5^3x + 2 = 5^2x + 3

=> 5^3x - 5^2x = 3 - 2

=> 5^x = 1

=> 5^x = 5⁰

=> x = 0

Vậy x = 0

Answer 4

a) (x - 2)² = 9.16

\(\Rightarrow\) (x-2)² = 144

\(\Leftrightarrow\) (x-2)² = 12²

\(\Rightarrow\) x - 2 = 12

\(\Rightarrow\) x = 14

b) (x - 1)³ = 8

\(\Leftrightarrow\) (x - 1 )³ = 2³

\(\Rightarrow\) x - 1 = 2

\(\Rightarrow\) x = 3