I have a question

Question

X² + 10x + 25 =81

Answer 1

Note that the left side is a perfect square.  If we rewrite the left side as a square, all that is needed to do is take the square root of each side.

 

x² + 10x + 25 = 81

 

(x+5)² = 81

 

√(x + 5)² = √81

 

|x + 5| = 9

 

Therefore,  x + 5 = 9    and x + 5 = -9

 

and  x = 9 - 5 = 4,    and    x = -9 - 5 = -14.   Be sure to CHECK!