What number must be added to the expression below to complete the square x^2+8x-5=15

Add 16 to both sides.

General Formulas and Concepts:

Pre-Alg

Equality Properties

Algebra I

Completing the Square: b/2a

Step-by-step explanation:

Step 1: Define expression

x² + 8x - 5 = 15

Step 2: Solve

Isolate x terms:                    x² + 8x = 20Complete the Square:        (x² + 8x + 16) = 20 + 16Simplify:                               (x + 4)² = 36

A= r2 × 3.14 7x7 ↓ ↓ 49 × 3.14 = 153.86 → 153.9

Don’t worry about it