Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(x−9)(x+5)
Evaluate
x2−4x−45
Rewrite the expression
x2+(5−9)x−45
Calculate
x2+5x−9x−45
Rewrite the expression
x×x+x×5−9x−9×5
Factor out x from the expression
x(x+5)−9x−9×5
Factor out −9 from the expression
x(x+5)−9(x+5)
Solution
(x−9)(x+5)
Show Solution
Find the roots
x1=−5,x2=9
Evaluate
x2−4x−45
To find the roots of the expression,set the expression equal to 0
x2−4x−45=0
Factor the expression
More Steps
Evaluate
x2−4x−45
Rewrite the expression
x2+(5−9)x−45
Calculate
x2+5x−9x−45
Rewrite the expression
x×x+x×5−9x−9×5
Factor out x from the expression
x(x+5)−9x−9×5
Factor out −9 from the expression
x(x+5)−9(x+5)
Factor out x+5 from the expression
(x−9)(x+5)
(x−9)(x+5)=0
When the product of factors equals 0,at least one factor is 0
x−9=0x+5=0
Solve the equation for x
More Steps
Evaluate
x−9=0
Move the constant to the right-hand side and change its sign
x=0+9
Removing 0 doesn't change the value,so remove it from the expression
x=9
x=9x+5=0
Solve the equation for x
More Steps
Evaluate
x+5=0
Move the constant to the right-hand side and change its sign
x=0−5
Removing 0 doesn't change the value,so remove it from the expression
x=−5
x=9x=−5
Solution
x1=−5,x2=9
Show Solution