Question
Find the roots
x1=32−22,x2=32+22
Alternative Form
x1≈−0.276142,x2≈1.609476
Evaluate
9x2−12x−4
To find the roots of the expression,set the expression equal to 0
9x2−12x−4=0
Substitute a=9,b=−12 and c=−4 into the quadratic formula x=2a−b±b2−4ac
x=2×912±(−12)2−4×9(−4)
Simplify the expression
x=1812±(−12)2−4×9(−4)
Simplify the expression
More Steps

Evaluate
(−12)2−4×9(−4)
Multiply
More Steps

Multiply the terms
4×9(−4)
Rewrite the expression
−4×9×4
Multiply the terms
−144
(−12)2−(−144)
Rewrite the expression
122−(−144)
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+144
Evaluate the power
144+144
Add the numbers
288
x=1812±288
Simplify the radical expression
More Steps

Evaluate
288
Write the expression as a product where the root of one of the factors can be evaluated
144×2
Write the number in exponential form with the base of 12
122×2
The root of a product is equal to the product of the roots of each factor
122×2
Reduce the index of the radical and exponent with 2
122
x=1812±122
Separate the equation into 2 possible cases
x=1812+122x=1812−122
Simplify the expression
More Steps

Evaluate
x=1812+122
Divide the terms
More Steps

Evaluate
1812+122
Rewrite the expression
186(2+22)
Cancel out the common factor 6
32+22
x=32+22
x=32+22x=1812−122
Simplify the expression
More Steps

Evaluate
x=1812−122
Divide the terms
More Steps

Evaluate
1812−122
Rewrite the expression
186(2−22)
Cancel out the common factor 6
32−22
x=32−22
x=32+22x=32−22
Solution
x1=32−22,x2=32+22
Alternative Form
x1≈−0.276142,x2≈1.609476
Show Solution
