Solve (4x 7)-(x^3)

Question

Simplify the expression

28 x - x^{3}

Evaluate

(4 x \times 7) - x^{3}

Solution

28 x - x^{3}

Show Solution

x (28 - x^{2})

Evaluate

(4 x \times 7) - x^{3}

Multiply the terms

28 x - x^{3}

Rewrite the expression

x \times 28 - x \times x^{2}

Solution

x (28 - x^{2})

Show Solution

x_{1} = - 27, x_{2} = 0, x_{3} = 27

Alternative Form

x_{1} \approx - 5.291503, x_{2} = 0, x_{3} \approx 5.291503

Evaluate

(4 x \times 7) - (x^{3})

To find the roots of the expression,set the expression equal to 0

(4 x \times 7) - (x^{3}) = 0

Multiply the terms

28 x - (x^{3}) = 0

Calculate

28 x - x^{3} = 0

Factor the expression

x (28 - x^{2}) = 0

Separate the equation into 2 possible cases

x = 0 28 - x^{2} = 0

Solve the equation

More Steps

Evaluate

28 - x^{2} = 0

Move the constant to the right-hand side and change its sign

- x^{2} = 0 - 28

Removing 0 doesn't change the value,so remove it from the expression

- x^{2} = - 28

Change the signs on both sides of the equation

x^{2} = 28

Take the root of both sides of the equation and remember to use both positive and negative roots

x = \pm 28

Simplify the expression

More Steps

Evaluate

28

Write the expression as a product where the root of one of the factors can be evaluated

4 \times 7

Write the number in exponential form with the base of 2

2^{2} \times 7

The root of a product is equal to the product of the roots of each factor

2^{2} \times 7

Reduce the index of the radical and exponent with 2

27

x = \pm 27

Separate the equation into 2 possible cases

x = 27 x = - 27

x = 0 x = 27 x = - 27

Solution

x_{1} = - 27, x_{2} = 0, x_{3} = 27

Alternative Form

x_{1} \approx - 5.291503, x_{2} = 0, x_{3} \approx 5.291503

Show Solution