Question

a)(2x -1)mũ2 = 25 b)(-3)mũx + 3.5 = -12

Answer 1

a: (2x-1)²=25

=>\(\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)

b: \(\left(-3\right)^x+3\cdot5=-12\)

=>\(\left(-3\right)^x=-12-15=-27\)

=>\(\left(-3\right)^x=\left(-3\right)^3\)

=>x=3

Answer 2

a, (2x - 1)² = 25 = 5²

=> 2x - 1 = 5 => 2x = 6 => x = 3

b,(-3)^x + 3 . 5 = -12

=> (-3)^x + 15 = -12

=> (-3)^x = -27

=> (-3)^x = (-3)³

=> x = 3