Question
Simplify the expression
40−105x2
Evaluate
8×5−105x2
Solution
40−105x2
Show Solution

Factor the expression
5(8−21x2)
Evaluate
8×5−105x2
Multiply the numbers
40−105x2
Solution
5(8−21x2)
Show Solution

Find the roots
x1=−21242,x2=21242
Alternative Form
x1≈−0.617213,x2≈0.617213
Evaluate
8×5−105x2
To find the roots of the expression,set the expression equal to 0
8×5−105x2=0
Multiply the numbers
40−105x2=0
Move the constant to the right-hand side and change its sign
−105x2=0−40
Removing 0 doesn't change the value,so remove it from the expression
−105x2=−40
Change the signs on both sides of the equation
105x2=40
Divide both sides
105105x2=10540
Divide the numbers
x2=10540
Cancel out the common factor 5
x2=218
Take the root of both sides of the equation and remember to use both positive and negative roots
x=±218
Simplify the expression
More Steps

Evaluate
218
To take a root of a fraction,take the root of the numerator and denominator separately
218
Simplify the radical expression
More Steps

Evaluate
8
Write the expression as a product where the root of one of the factors can be evaluated
4×2
Write the number in exponential form with the base of 2
22×2
The root of a product is equal to the product of the roots of each factor
22×2
Reduce the index of the radical and exponent with 2
22
2122
Multiply by the Conjugate
21×2122×21
Multiply the numbers
More Steps

Evaluate
2×21
The product of roots with the same index is equal to the root of the product
2×21
Calculate the product
42
21×21242
When a square root of an expression is multiplied by itself,the result is that expression
21242
x=±21242
Separate the equation into 2 possible cases
x=21242x=−21242
Solution
x1=−21242,x2=21242
Alternative Form
x1≈−0.617213,x2≈0.617213
Show Solution
