Solve x^2+4x=20 by completing the square.

Answer 1

x²+4x=20

To find the c term, c=(b/2)²

c=(4/2)²

c=4

Add 4 to both sides

x²+4x+4=20+4

Factor

(x+2)²=24

Take the square root of both sides

√(x+2)²=±√24 Simplify

(x+2)=±2√6

(x+2)=±2√6 Subtract 2 from both sides

x=-2±2√6