Question
Factor the expression
Factor
4(b2+3b+9)
Evaluate
4b2+12b+36
Solution
4(b2+3b+9)
Show Solution
Find the roots
Find the roots of the algebra expression
b1=−23−233i,b2=−23+233i
Alternative Form
b1≈−1.5−2.598076i,b2≈−1.5+2.598076i
Evaluate
4b2+12b+36
To find the roots of the expression,set the expression equal to 0
4b2+12b+36=0
Substitute a=4,b=12 and c=36 into the quadratic formula b=2a−b±b2−4ac
b=2×4−12±122−4×4×36
Simplify the expression
b=8−12±122−4×4×36
Simplify the expression
More Steps

Evaluate
122−4×4×36
Multiply the terms
More Steps

Multiply the terms
4×4×36
Multiply the terms
16×36
Multiply the numbers
576
122−576
Evaluate the power
144−576
Subtract the numbers
−432
b=8−12±−432
Simplify the radical expression
More Steps

Evaluate
−432
Evaluate the power
432×−1
Evaluate the power
432×i
Evaluate the power
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Evaluate
432
Write the expression as a product where the root of one of the factors can be evaluated
144×3
Write the number in exponential form with the base of 12
122×3
The root of a product is equal to the product of the roots of each factor
122×3
Reduce the index of the radical and exponent with 2
123
123×i
b=8−12±123×i
Separate the equation into 2 possible cases
b=8−12+123×ib=8−12−123×i
Simplify the expression
More Steps

Evaluate
b=8−12+123×i
Divide the terms
More Steps

Evaluate
8−12+123×i
Rewrite the expression
84(−3+33×i)
Cancel out the common factor 4
2−3+33×i
Use b−a=−ba=−ba to rewrite the fraction
−23−33×i
Simplify
−23+233i
b=−23+233i
b=−23+233ib=8−12−123×i
Simplify the expression
More Steps

Evaluate
b=8−12−123×i
Divide the terms
More Steps

Evaluate
8−12−123×i
Rewrite the expression
84(−3−33×i)
Cancel out the common factor 4
2−3−33×i
Use b−a=−ba=−ba to rewrite the fraction
−23+33×i
Simplify
−23−233i
b=−23−233i
b=−23+233ib=−23−233i
Solution
b1=−23−233i,b2=−23+233i
Alternative Form
b1≈−1.5−2.598076i,b2≈−1.5+2.598076i
Show Solution