Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=36−39,x2=36+39
Alternative Form
x1≈−0.081666,x2≈4.081666
Evaluate
3x2−12x−1=0
Substitute a=3,b=−12 and c=−1 into the quadratic formula x=2a−b±b2−4ac
x=2×312±(−12)2−4×3(−1)
Simplify the expression
x=612±(−12)2−4×3(−1)
Simplify the expression
More Steps

Evaluate
(−12)2−4×3(−1)
Multiply
More Steps

Multiply the terms
4×3(−1)
Any expression multiplied by 1 remains the same
−4×3
Multiply the terms
−12
(−12)2−(−12)
Rewrite the expression
122−(−12)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
122+12
Evaluate the power
144+12
Add the numbers
156
x=612±156
Simplify the radical expression
More Steps

Evaluate
156
Write the expression as a product where the root of one of the factors can be evaluated
4×39
Write the number in exponential form with the base of 2
22×39
The root of a product is equal to the product of the roots of each factor
22×39
Reduce the index of the radical and exponent with 2
239
x=612±239
Separate the equation into 2 possible cases
x=612+239x=612−239
Simplify the expression
More Steps

Evaluate
x=612+239
Divide the terms
More Steps

Evaluate
612+239
Rewrite the expression
62(6+39)
Cancel out the common factor 2
36+39
x=36+39
x=36+39x=612−239
Simplify the expression
More Steps

Evaluate
x=612−239
Divide the terms
More Steps

Evaluate
612−239
Rewrite the expression
62(6−39)
Cancel out the common factor 2
36−39
x=36−39
x=36+39x=36−39
Solution
x1=36−39,x2=36+39
Alternative Form
x1≈−0.081666,x2≈4.081666
Show Solution
