Question

a)\(-x-\)\(\dfrac{2}{3}\)=\(\dfrac{-6}{7}\)

c)\(x^2=16\)

d)\(2^{x-1}=64\)

Answer 1

a.

\(-x-\dfrac{2}{3}=\dfrac{-6}{7}\)

\(-x=\dfrac{-6}{7}+\dfrac{2}{3}\)

\(-x=\dfrac{-4}{21}\)

\(\Rightarrow x=\dfrac{4}{21}\)

Vậy\(x=\dfrac{4}{21}\)

b.

\(x^2=16\)

\(x^2=4^2\)

\(\Rightarrow x=4\)

Vậy x = 4

c.

\(2^{x-1}=64\)

\(2^{x-1}=2^6\)

\(\Rightarrow x-1=6\)

\(x=6+1\)

\(x=7\)

Vậy x = 7

Answer 2

Giải:

a) \(-x-\dfrac{2}{3}=-\dfrac{6}{7}\)

\(\Leftrightarrow-x=-\dfrac{6}{7}+\dfrac{2}{3}\)

\(\Leftrightarrow-x=-\dfrac{4}{21}\)

\(\Leftrightarrow x=\dfrac{4}{21}\)

b) \(x^2=16\)

\(x^2=4^2\)

Vì \(2=2\)

Nên \(x=4\)

c) \(2^{x-1}=64\)

\(2^{x-1}=2^6\)

Vì \(2=2\)

Nên \(x-1=6\)

\(\Leftrightarrow x=6+1\)

\(\Leftrightarrow x=7\)

Chúc bạn học tốt!

Answer 3

\(a.\left(-x\right)-\dfrac{2}{3}=-\dfrac{6}{7}\)

\(\left(-x\right)=-\dfrac{6}{7}+\dfrac{2}{3}\)

\(\left(-x\right)=-\dfrac{4}{21}\)

\(\Rightarrow x=\dfrac{4}{21}\)

Vậy \(x=\dfrac{4}{21}\)

\(b.x^2=16\)

\(x^2=4^2\)

\(\Rightarrow x=4\)

Vậy \(x=4\)

\(c.2^{x-1}=64\)

\(2^{x-1}=2^6\)

\(\Rightarrow x-1=6\)

\(\Rightarrow x=7\)

Vậy \(x=7\)