Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(x−45)(x+42)
Evaluate
x2−3x−1890
Rewrite the expression
x2+(42−45)x−1890
Calculate
x2+42x−45x−1890
Rewrite the expression
x×x+x×42−45x−45×42
Factor out x from the expression
x(x+42)−45x−45×42
Factor out −45 from the expression
x(x+42)−45(x+42)
Solution
(x−45)(x+42)
Show Solution
Find the roots
x1=−42,x2=45
Evaluate
x2−3x−1890
To find the roots of the expression,set the expression equal to 0
x2−3x−1890=0
Factor the expression
More Steps
Evaluate
x2−3x−1890
Rewrite the expression
x2+(42−45)x−1890
Calculate
x2+42x−45x−1890
Rewrite the expression
x×x+x×42−45x−45×42
Factor out x from the expression
x(x+42)−45x−45×42
Factor out −45 from the expression
x(x+42)−45(x+42)
Factor out x+42 from the expression
(x−45)(x+42)
(x−45)(x+42)=0
When the product of factors equals 0,at least one factor is 0
x−45=0x+42=0
Solve the equation for x
More Steps
Evaluate
x−45=0
Move the constant to the right-hand side and change its sign
x=0+45
Removing 0 doesn't change the value,so remove it from the expression
x=45
x=45x+42=0
Solve the equation for x
More Steps
Evaluate
x+42=0
Move the constant to the right-hand side and change its sign
x=0−42
Removing 0 doesn't change the value,so remove it from the expression
x=−42
x=45x=−42
Solution
x1=−42,x2=45
Show Solution