Algebra
Calculus
Trigonometry
Matrix
Question
Simplify the expression
x2−8x−2
Evaluate
x2−8x−2−0
Solution
x2−8x−2
Show Solution
Find the roots
x1=4−32,x2=4+32
Alternative Form
x1≈−0.242641,x2≈8.242641
Evaluate
x2−8x−2−0
To find the roots of the expression,set the expression equal to 0
x2−8x−2−0=0
Removing 0 doesn't change the value,so remove it from the expression
x2−8x−2=0
Substitute a=1,b=−8 and c=−2 into the quadratic formula x=2a−b±b2−4ac
x=28±(−8)2−4(−2)
Simplify the expression
More Steps
Evaluate
(−8)2−4(−2)
Multiply the numbers
More Steps
Evaluate
4(−2)
Multiplying or dividing an odd number of negative terms equals a negative
−4×2
Multiply the numbers
−8
(−8)2−(−8)
Rewrite the expression
82−(−8)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
82+8
Evaluate the power
64+8
Add the numbers
72
x=28±72
Simplify the radical expression
More Steps
Evaluate
72
Write the expression as a product where the root of one of the factors can be evaluated
36×2
Write the number in exponential form with the base of 6
62×2
The root of a product is equal to the product of the roots of each factor
62×2
Reduce the index of the radical and exponent with 2
62
x=28±62
Separate the equation into 2 possible cases
x=28+62x=28−62
Simplify the expression
More Steps
Evaluate
x=28+62
Divide the terms
More Steps
Evaluate
28+62
Rewrite the expression
22(4+32)
Reduce the fraction
4+32
x=4+32
x=4+32x=28−62
Simplify the expression
More Steps
Evaluate
x=28−62
Divide the terms
More Steps
Evaluate
28−62
Rewrite the expression
22(4−32)
Reduce the fraction
4−32
x=4−32
x=4+32x=4−32
Solution
x1=4−32,x2=4+32
Alternative Form
x1≈−0.242641,x2≈8.242641
Show Solution