Question
Factor the expression
3(n−9)(n+5)
Evaluate
3n2−12n−135
Rewrite the expression
3n2−3×4n−3×45
Factor out 3 from the expression
3(n2−4n−45)
Solution
More Steps

Evaluate
n2−4n−45
Rewrite the expression
n2+(5−9)n−45
Calculate
n2+5n−9n−45
Rewrite the expression
n×n+n×5−9n−9×5
Factor out n from the expression
n(n+5)−9n−9×5
Factor out −9 from the expression
n(n+5)−9(n+5)
Factor out n+5 from the expression
(n−9)(n+5)
3(n−9)(n+5)
Show Solution

Find the roots
n1=−5,n2=9
Evaluate
3n2−12n−135
To find the roots of the expression,set the expression equal to 0
3n2−12n−135=0
Factor the expression
More Steps

Evaluate
3n2−12n−135
Rewrite the expression
3n2−3×4n−3×45
Factor out 3 from the expression
3(n2−4n−45)
Factor the expression
More Steps

Evaluate
n2−4n−45
Rewrite the expression
n2+(5−9)n−45
Calculate
n2+5n−9n−45
Rewrite the expression
n×n+n×5−9n−9×5
Factor out n from the expression
n(n+5)−9n−9×5
Factor out −9 from the expression
n(n+5)−9(n+5)
Factor out n+5 from the expression
(n−9)(n+5)
3(n−9)(n+5)
3(n−9)(n+5)=0
Divide the terms
(n−9)(n+5)=0
When the product of factors equals 0,at least one factor is 0
n−9=0n+5=0
Solve the equation for n
More Steps

Evaluate
n−9=0
Move the constant to the right-hand side and change its sign
n=0+9
Removing 0 doesn't change the value,so remove it from the expression
n=9
n=9n+5=0
Solve the equation for n
More Steps

Evaluate
n+5=0
Move the constant to the right-hand side and change its sign
n=0−5
Removing 0 doesn't change the value,so remove it from the expression
n=−5
n=9n=−5
Solution
n1=−5,n2=9
Show Solution
