Question

\(b,6x^3-8=40\)

\(a,5^{x+1}:5=5^4\)

Answer 1

\(6x^3-8=40\\ 6x^3=40+8=48\\x^3=\dfrac{48}{6}=8=2^3\\ Vậy:x=2\\ ---\\ 5^{x+1}:5=5^4\\5^{x+1}:5^1=5^4\\ 5^{x+1-1}=5^4\\ 5^x=5^4\\ Vậy:x=4\)

Answer 2

\(a,\) \(6x^3-8=40\)

\(6x^3=40+8\)

\(6x^3=48\)

\(x^3=8\)

\(x^3=8\)

\(x^3=2^3\)

\(x=2\)

Vậy \(x=2\)

\(b,\) \(5^{x+1}:5=5^4\)

\(5^{x+1-1}=5^4\)

\(5^x=5^4\)

\(x=4\)

Vậy \(x=4\)