Review question

# How many real roots does $8^x+4=4^x+2^{x+2}$ have? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R7606

## Suggestion

The equation $8^x+4=4^x+2^{x+2}$ has

1. no real solutions;

2. one real solution;

3. two real solutions;

4. three real solutions.

[A real solution is one that lies on the number line.]

This equation looks difficult because the unknown $x$ is in the exponents. Could we make a substitution to make it look more like a familiar type of equation?