Question

Answer 1

Giúp mình với

Answer 2

Bài 3b:

a. 2^x = 16

<=> 2^x = 2⁴

<=> x = 4

b. \(\left(\dfrac{-3}{7}\right)^x=\dfrac{-27}{343}\)

<=> \(\left(\dfrac{-3}{7}\right)^x=\left(\dfrac{-3}{7}\right)^3\)

<=> x = 3

d. x⁵ = 243

<=> \(x=\sqrt[5]{243}\)

<=> x = 3

e. x² = 36

<=> x = \(\sqrt{36}\)

<=> x = 6

Bài 3a:

f. x⁴ = \(\dfrac{16}{81}\)

<=> \(x^4=\left(\dfrac{2}{3}\right)^4\) 

<=> x = \(\dfrac{2}{3}\)

g. x² = 0,25

<=> \(x=\sqrt{0,25}\)

<=> x = 0,5

h. \(\left(-\dfrac{1}{2}\right)^2.x=\left(-\dfrac{1}{2}\right)^5\)

<=> \(x=\left(-\dfrac{1}{2}\right)^5:\left(-\dfrac{1}{2}\right)^2\)

<=> \(x=\left(-\dfrac{1}{2}\right)^3\)

<=> \(x=\dfrac{-1}{8}\)

i. (2x - 3)⁵ = -243

<=> 2x - 3 = \(-\sqrt[5]{243}\)

<=> 2x - 3 = -3

<=> 2x = 0

<=> x = 0

j. (1 - 2x)² = 16

<=> (1 - 2x)² - 4² = 0

<=> (1 - 2x + 4)(1 - 2x - 4) = 0

<=> (5 - 2x)(-3 - 2x) = 0

<=> \(\left[{}\begin{matrix}5-2x=0\\-3-2x=0\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=\dfrac{-3}{2}\end{matrix}\right.\)