Questions: Complete the square. Fill in the number that makes the polynomial a perfect-square quadratic. j^2 + 4j + □

Complete the square for the quadratic expression \( j^{2} + 4j + \square \).

Identify the coefficient of the linear term.

The coefficient of \( j \) is \( 4 \).

Calculate half of the coefficient of the linear term.

Half of \( 4 \) is \( 2 \).

Square the result to find the constant term.

Squaring \( 2 \) gives \( 4 \).

The number that makes the polynomial a perfect-square quadratic is \( \boxed{4} \).

The number that completes the square is \( \boxed{4} \).