Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(x−9)(x+8)
Evaluate
x2−x−72
Rewrite the expression
x2+(8−9)x−72
Calculate
x2+8x−9x−72
Rewrite the expression
x×x+x×8−9x−9×8
Factor out x from the expression
x(x+8)−9x−9×8
Factor out −9 from the expression
x(x+8)−9(x+8)
Solution
(x−9)(x+8)
Show Solution
Find the roots
x1=−8,x2=9
Evaluate
x2−x−72
To find the roots of the expression,set the expression equal to 0
x2−x−72=0
Factor the expression
More Steps
Evaluate
x2−x−72
Rewrite the expression
x2+(8−9)x−72
Calculate
x2+8x−9x−72
Rewrite the expression
x×x+x×8−9x−9×8
Factor out x from the expression
x(x+8)−9x−9×8
Factor out −9 from the expression
x(x+8)−9(x+8)
Factor out x+8 from the expression
(x−9)(x+8)
(x−9)(x+8)=0
When the product of factors equals 0,at least one factor is 0
x−9=0x+8=0
Solve the equation for x
More Steps
Evaluate
x−9=0
Move the constant to the right-hand side and change its sign
x=0+9
Removing 0 doesn't change the value,so remove it from the expression
x=9
x=9x+8=0
Solve the equation for x
More Steps
Evaluate
x+8=0
Move the constant to the right-hand side and change its sign
x=0−8
Removing 0 doesn't change the value,so remove it from the expression
x=−8
x=9x=−8
Solution
x1=−8,x2=9
Show Solution