Answer:
a² = b² -w² +2wx
Explanation:
The algebra is pretty straightforward. Expand the expression in parentheses and add x².
b² -(w -x)² = e² = a² -x²
b² -(w² -2wx +x²) = a² -x² . . . . . expand the square
b² -w² +2wx -x² = a² -x² . . . . . . distribute the minus sign
b² -w² +2wx = a² . . . . . . . . . . . . add x²