Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=31−3,x2=31+3
Alternative Form
x1≈−0.244017,x2≈0.910684
Evaluate
9x2−6x−2=0
Substitute a=9,b=−6 and c=−2 into the quadratic formula x=2a−b±b2−4ac
x=2×96±(−6)2−4×9(−2)
Simplify the expression
x=186±(−6)2−4×9(−2)
Simplify the expression
More Steps

Evaluate
(−6)2−4×9(−2)
Multiply
More Steps

Multiply the terms
4×9(−2)
Rewrite the expression
−4×9×2
Multiply the terms
−72
(−6)2−(−72)
Rewrite the expression
62−(−72)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
62+72
Evaluate the power
36+72
Add the numbers
108
x=186±108
Simplify the radical expression
More Steps

Evaluate
108
Write the expression as a product where the root of one of the factors can be evaluated
36×3
Write the number in exponential form with the base of 6
62×3
The root of a product is equal to the product of the roots of each factor
62×3
Reduce the index of the radical and exponent with 2
63
x=186±63
Separate the equation into 2 possible cases
x=186+63x=186−63
Simplify the expression
More Steps

Evaluate
x=186+63
Divide the terms
More Steps

Evaluate
186+63
Rewrite the expression
186(1+3)
Cancel out the common factor 6
31+3
x=31+3
x=31+3x=186−63
Simplify the expression
More Steps

Evaluate
x=186−63
Divide the terms
More Steps

Evaluate
186−63
Rewrite the expression
186(1−3)
Cancel out the common factor 6
31−3
x=31−3
x=31+3x=31−3
Solution
x1=31−3,x2=31+3
Alternative Form
x1≈−0.244017,x2≈0.910684
Show Solution
