Question

What number must you add to complete the square? x^2+26x=23

Answer 1

• x²+26x=23

For 2ab to complete in (a+b)² formula

• 2ab=26

a=1

• 2b=26
• b=13
• b²=169

So 169 must be added

Answer 2

169

Explanation:

x²+26x=23

=> to complete the square, the equation should be : x²+26x + (26/2)² = 23 + (26/2)²

<=> x² +26x + 13² = 23 + 13²

<=> x² +26x +169 = 23 + 169

<=> (x+13)² = 192

so, (x+13)² is the square form , and 169 must be added to complete the square