Question

What is the first incorrect step in solving the following exponential equation?

Given: 1622+1 = 25-2
2x+1
Step 1: (24) ²z+¹ = 25–z
Step 2: 24(2x+1)= 25-2
Step 3: 28z+1=25-z
Step 4: 8x + 15-x
Step 5: 8x + x = 5-1
Step 6: 9x = 4
Step 7:
9x
Step 8: T
=

Answer 1

The first incorrect step is Step 4: "8x + 15-x."
The equation at this step should be "8z + 15 = 25 - z," not "8x + 15-x."

The correct equation at this point should have been: 8z + 15 = 25 - z