Question
Find the roots
x1=23−35,x2=23+35
Alternative Form
x1≈−1.854102,x2≈4.854102
Evaluate
x2−3x−9
To find the roots of the expression,set the expression equal to 0
x2−3x−9=0
Substitute a=1,b=−3 and c=−9 into the quadratic formula x=2a−b±b2−4ac
x=23±(−3)2−4(−9)
Simplify the expression
More Steps

Evaluate
(−3)2−4(−9)
Multiply the numbers
More Steps

Evaluate
4(−9)
Multiplying or dividing an odd number of negative terms equals a negative
−4×9
Multiply the numbers
−36
(−3)2−(−36)
Rewrite the expression
32−(−36)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
32+36
Evaluate the power
9+36
Add the numbers
45
x=23±45
Simplify the radical expression
More Steps

Evaluate
45
Write the expression as a product where the root of one of the factors can be evaluated
9×5
Write the number in exponential form with the base of 3
32×5
The root of a product is equal to the product of the roots of each factor
32×5
Reduce the index of the radical and exponent with 2
35
x=23±35
Separate the equation into 2 possible cases
x=23+35x=23−35
Solution
x1=23−35,x2=23+35
Alternative Form
x1≈−1.854102,x2≈4.854102
Show Solution
