The image contains a mathematical expression and a variable assignment.

Mathematical Expression:

• The core expression appears to be: \( (4-5)^{2} = g(y+4) - 21 \)

Variable Assignment:

• There is a variable \( g \) which is assigned a value.
• The assignment is: \( g = \frac{1}{7} \)

Note: The full context or purpose of this expression and assignment is not provided in the image.