Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(a−5)(a−4)
Evaluate
a2−9a+20
Rewrite the expression
a2+(−4−5)a+20
Calculate
a2−4a−5a+20
Rewrite the expression
a×a−a×4−5a+5×4
Factor out a from the expression
a(a−4)−5a+5×4
Factor out −5 from the expression
a(a−4)−5(a−4)
Solution
(a−5)(a−4)
Show Solution
Find the roots
a1=4,a2=5
Evaluate
a2−9a+20
To find the roots of the expression,set the expression equal to 0
a2−9a+20=0
Factor the expression
More Steps
Evaluate
a2−9a+20
Rewrite the expression
a2+(−4−5)a+20
Calculate
a2−4a−5a+20
Rewrite the expression
a×a−a×4−5a+5×4
Factor out a from the expression
a(a−4)−5a+5×4
Factor out −5 from the expression
a(a−4)−5(a−4)
Factor out a−4 from the expression
(a−5)(a−4)
(a−5)(a−4)=0
When the product of factors equals 0,at least one factor is 0
a−5=0a−4=0
Solve the equation for a
More Steps
Evaluate
a−5=0
Move the constant to the right-hand side and change its sign
a=0+5
Removing 0 doesn't change the value,so remove it from the expression
a=5
a=5a−4=0
Solve the equation for a
More Steps
Evaluate
a−4=0
Move the constant to the right-hand side and change its sign
a=0+4
Removing 0 doesn't change the value,so remove it from the expression
a=4
a=5a=4
Solution
a1=4,a2=5
Show Solution