Solve 4x^37-x - ScanMath

Question

Simplify the expression

28 x^{3} - x

Evaluate

4 x^{3} \times 7 - x

Solution

28 x^{3} - x

Show Solution

x (28 x^{2} - 1)

Evaluate

4 x^{3} \times 7 - x

Multiply the terms

28 x^{3} - x

Rewrite the expression

x \times 28 x^{2} - x

Solution

x (28 x^{2} - 1)

Show Solution

x_{1} = - \frac{7}{14}, x_{2} = 0, x_{3} = \frac{7}{14}

Alternative Form

x_{1} \approx - 0.188982, x_{2} = 0, x_{3} \approx 0.188982

Evaluate

4 x^{3} \times 7 - x

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

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

Multiply the terms

28 x^{3} - x = 0

Factor the expression

x (28 x^{2} - 1) = 0

Separate the equation into 2 possible cases

x = 0 28 x^{2} - 1 = 0

Solve the equation

More Steps

Evaluate

28 x^{2} - 1 = 0

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

28 x^{2} = 0 + 1

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

28 x^{2} = 1

Divide both sides

\frac{28 x ^{2}}{28} = \frac{1}{28}

Divide the numbers

x^{2} = \frac{1}{28}

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

x = \pm \frac{1}{28}

Simplify the expression

More Steps

Evaluate

\frac{1}{28}

To take a root of a fraction,take the root of the numerator and denominator separately

\frac{1}{28}

Simplify the radical expression

\frac{1}{28}

Simplify the radical expression

\frac{1}{2 7}

Multiply by the Conjugate

\frac{7}{2 7 \times 7}

Multiply the numbers

\frac{7}{14}

x = \pm \frac{7}{14}

Separate the equation into 2 possible cases

x = \frac{7}{14} x = - \frac{7}{14}

x = 0 x = \frac{7}{14} x = - \frac{7}{14}

Solution

x_{1} = - \frac{7}{14}, x_{2} = 0, x_{3} = \frac{7}{14}

Alternative Form

x_{1} \approx - 0.188982, x_{2} = 0, x_{3} \approx 0.188982

Show Solution