Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(x−4)(x+2)
Evaluate
x2−2x−8
Rewrite the expression
x2+(2−4)x−8
Calculate
x2+2x−4x−8
Rewrite the expression
x×x+x×2−4x−4×2
Factor out x from the expression
x(x+2)−4x−4×2
Factor out −4 from the expression
x(x+2)−4(x+2)
Solution
(x−4)(x+2)
Show Solution
Find the roots
x1=−2,x2=4
Evaluate
x2−2x−8
To find the roots of the expression,set the expression equal to 0
x2−2x−8=0
Factor the expression
More Steps
Evaluate
x2−2x−8
Rewrite the expression
x2+(2−4)x−8
Calculate
x2+2x−4x−8
Rewrite the expression
x×x+x×2−4x−4×2
Factor out x from the expression
x(x+2)−4x−4×2
Factor out −4 from the expression
x(x+2)−4(x+2)
Factor out x+2 from the expression
(x−4)(x+2)
(x−4)(x+2)=0
When the product of factors equals 0,at least one factor is 0
x−4=0x+2=0
Solve the equation for x
More Steps
Evaluate
x−4=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=4x+2=0
Solve the equation for x
More Steps
Evaluate
x+2=0
Move the constant to the right-hand side and change its sign
x=0−2
Removing 0 doesn't change the value,so remove it from the expression
x=−2
x=4x=−2
Solution
x1=−2,x2=4
Show Solution