Answer
Lea started with the correct equation. However, she forgot to multiply the 9 when she cancelled out the 20 and 5 in the fraction. She also failed to write the degree symbol with the "F."
Work Step by Step
The correct solution is as follows:
$$ \frac{9\cdot 20}{5} +32 \\ 9\cdot 4 + 32 \\ 36 + 32 \\ 68^{\circ}F $$