Question

Answer 1

c)

\(5^{x+1}-2020^0=2^3\cdot3\\ 5^x\cdot5-1=24\\ 5^x\cdot5=24+1\\ 5^x\cdot5=25\\ 5^x=25:5\\ 5^x=5\\ =>x=1\)

b)

\(2448:\left[119-\left(x-6\right)\right]=24\\ 119-x+6=2448:24\\ 119-x+6=102\\ -x=102-119-6\\ -x=-23\\ =>x=23\)

d)

ummmmm câu d 10≤x≤1 là sao nhỉ=))

e)

\(\left(2x-1\right)^2-2^2=21\\ \left(2x-1\right)^2=21+4\\ \left(2x-1\right)^2=25\\ \left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)