Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(9−x)(9+x)
Evaluate
81−x2
Rewrite the expression in exponential form
92−x2
Solution
(9−x)(9+x)
Show Solution
Find the roots
x1=−9,x2=9
Evaluate
81−x2
To find the roots of the expression,set the expression equal to 0
81−x2=0
Move the constant to the right-hand side and change its sign
−x2=0−81
Removing 0 doesn't change the value,so remove it from the expression
−x2=−81
Change the signs on both sides of the equation
x2=81
Take the root of both sides of the equation and remember to use both positive and negative roots
x=±81
Simplify the expression
More Steps
Evaluate
81
Write the number in exponential form with the base of 9
92
Reduce the index of the radical and exponent with 2
9
x=±9
Separate the equation into 2 possible cases
x=9x=−9
Solution
x1=−9,x2=9
Show Solution