Question
Factor the expression
Factor
(x+4)(2x+1)
Evaluate
2x2+9x+4
Rewrite the expression
2x2+(1+8)x+4
Calculate
2x2+x+8x+4
Rewrite the expression
x×2x+x+4×2x+4
Factor out x from the expression
x(2x+1)+4×2x+4
Factor out 4 from the expression
x(2x+1)+4(2x+1)
Solution
(x+4)(2x+1)
Show Solution
Find the roots
Find the roots of the algebra expression
x1=−4,x2=−21
Alternative Form
x1=−4,x2=−0.5
Evaluate
2x2+9x+4
To find the roots of the expression,set the expression equal to 0
2x2+9x+4=0
Factor the expression
More Steps

Evaluate
2x2+9x+4
Rewrite the expression
2x2+(1+8)x+4
Calculate
2x2+x+8x+4
Rewrite the expression
x×2x+x+4×2x+4
Factor out x from the expression
x(2x+1)+4×2x+4
Factor out 4 from the expression
x(2x+1)+4(2x+1)
Factor out 2x+1 from the expression
(x+4)(2x+1)
(x+4)(2x+1)=0
When the product of factors equals 0,at least one factor is 0
x+4=02x+1=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=−42x+1=0
Solve the equation for x
More Steps

Evaluate
2x+1=0
Move the constant to the right-hand side and change its sign
2x=0−1
Removing 0 doesn't change the value,so remove it from the expression
2x=−1
Divide both sides
22x=2−1
Divide the numbers
x=2−1
Use b−a=−ba=−ba to rewrite the fraction
x=−21
x=−4x=−21
Solution
x1=−4,x2=−21
Alternative Form
x1=−4,x2=−0.5
Show Solution