5ln ( x + 8 ) solve the equation for x

You have not given an equation.

If we make it an equation, then we can solve for x.
  a = 5*ln(x +8)
  a/5 = ln(x +8) . . . . . . . divide by 5
  e^(a/5) = x +8 . . . . . . take the antilog
  e^(a/5) -8 = x . . . . . . . subtract 8

If your expression is equal to "a", then x is ...
  x = e^(a/5) -8

Carla is on the right track because she is finding the slopes of consecutive sides to check for right angles.

Step-by-step explanation:

The slope of the line passing through the points and is

Find the slope of the line passing through the points C(2, 3) and D(1, 2):

Find the slope of the line passing through the points D(1,2) and E(4,1):

These slopes have the product

so angle D is not a right angle.

Carla is on the right track because she is finding the slopes of consecutive sides to check for right angles.