Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(a−4)(a+2)
Evaluate
a2−2a−8
Rewrite the expression
a2+(2−4)a−8
Calculate
a2+2a−4a−8
Rewrite the expression
a×a+a×2−4a−4×2
Factor out a from the expression
a(a+2)−4a−4×2
Factor out −4 from the expression
a(a+2)−4(a+2)
Solution
(a−4)(a+2)
Show Solution
Find the roots
a1=−2,a2=4
Evaluate
a2−2a−8
To find the roots of the expression,set the expression equal to 0
a2−2a−8=0
Factor the expression
More Steps
Evaluate
a2−2a−8
Rewrite the expression
a2+(2−4)a−8
Calculate
a2+2a−4a−8
Rewrite the expression
a×a+a×2−4a−4×2
Factor out a from the expression
a(a+2)−4a−4×2
Factor out −4 from the expression
a(a+2)−4(a+2)
Factor out a+2 from the expression
(a−4)(a+2)
(a−4)(a+2)=0
When the product of factors equals 0,at least one factor is 0
a−4=0a+2=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=4a+2=0
Solve the equation for a
More Steps
Evaluate
a+2=0
Move the constant to the right-hand side and change its sign
a=0−2
Removing 0 doesn't change the value,so remove it from the expression
a=−2
a=4a=−2
Solution
a1=−2,a2=4
Show Solution