+0  
 
+2
750
1
avatar+319 

Rate me on the question-Solve this equation using an algebraic method: (x + 4)( x - 4) = 9

 Oct 12, 2016
 #1
avatar
+2

Solve for x:
(x-4) (x+4) = 9

Expand out terms of the left hand side:
x^2-16 = 9

Add 16 to both sides:
x^2 = 25

Take the square root of both sides:
Answer: |x = 5      or       x = -5

 Oct 12, 2016

1 Online Users