( 2^{3x} · 8^{x+5 }) / 16^{x-1 } = √2^{x-1}

^{I keep getting -17/3, but apparently the answer is -9??? :///}

Drazil Jun 2, 2019

#4**+1 **

**I AGREE WITH ALAN:**

**Solve for x over the real numbers: 2^(2 x + 19) = 2^((x - 1)/2)**

**Take the natural logarithm of both sides and use the identity log(a^b) = b log(a): log(2) (2 x + 19) = 1/2 log(2) (x - 1)**

**Divide both sides by log(2): 2 x + 19 = (x - 1)/2**

**Expand out terms of the right hand side: 2 x + 19 = x/2 - 1/2**

**Subtract x/2 + 19 from both sides: (3 x)/2 = -39/2**

**Multiply both sides by 2/3: x = -13**

Guest Jun 2, 2019