Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(5−x)(4+x)
Evaluate
20+x−x2
Rewrite the expression
20+(5−4)x−x2
Calculate
20+5x−4x−x2
Rewrite the expression
5×4+5x−x×4−x×x
Factor out 5 from the expression
5(4+x)−x×4−x×x
Factor out −x from the expression
5(4+x)−x(4+x)
Solution
(5−x)(4+x)
Show Solution
Find the roots
x1=−4,x2=5
Evaluate
20+x−x2
To find the roots of the expression,set the expression equal to 0
20+x−x2=0
Factor the expression
More Steps
Evaluate
20+x−x2
Rewrite the expression
20+(5−4)x−x2
Calculate
20+5x−4x−x2
Rewrite the expression
5×4+5x−x×4−x×x
Factor out 5 from the expression
5(4+x)−x×4−x×x
Factor out −x from the expression
5(4+x)−x(4+x)
Factor out 4+x from the expression
(5−x)(4+x)
(5−x)(4+x)=0
When the product of factors equals 0,at least one factor is 0
5−x=04+x=0
Solve the equation for x
More Steps
Evaluate
5−x=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
Change the signs on both sides of the equation
x=5
x=54+x=0
Solve the equation for x
More Steps
Evaluate
4+x=0
Move the constant to the right-hand side and change its sign
x=0−4
Removing 0 doesn't change the value,so remove it from the expression
x=−4
x=5x=−4
Solution
x1=−4,x2=5
Show Solution