Solve -5x x-4 - ScanMath

Question

Simplify the expression

- 5 x^{2} - 4

Evaluate

- 5 x \times x - 4

Solution

- 5 x^{2} - 4

Show Solution

x_{1} = - \frac{2 5}{5} i, x_{2} = \frac{2 5}{5} i

Alternative Form

x_{1} \approx - 0.894427 i, x_{2} \approx 0.894427 i

Evaluate

- 5 x \times x - 4

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

- 5 x \times x - 4 = 0

Multiply the terms

- 5 x^{2} - 4 = 0

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

- 5 x^{2} = 0 + 4

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

- 5 x^{2} = 4

Change the signs on both sides of the equation

5 x^{2} = - 4

Divide both sides

\frac{5 x ^{2}}{5} = \frac{- 4}{5}

Divide the numbers

x^{2} = \frac{- 4}{5}

Use \frac{- a}{b} = \frac{a}{- b} = - \frac{a}{b} to rewrite the fraction

x^{2} = - \frac{4}{5}

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

x = \pm - \frac{4}{5}

Simplify the expression

More Steps

Evaluate

- \frac{4}{5}

Evaluate the power

\frac{4}{5} \times - 1

Evaluate the power

\frac{4}{5} \times i

Evaluate the power

More Steps

Evaluate

\frac{4}{5}

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

\frac{4}{5}

Simplify the radical expression

\frac{2}{5}

Multiply by the Conjugate

\frac{2 5}{5 \times 5}

When a square root of an expression is multiplied by itself,the result is that expression

\frac{2 5}{5}

\frac{2 5}{5} i

x = \pm \frac{2 5}{5} i

Separate the equation into 2 possible cases

x = \frac{2 5}{5} i x = - \frac{2 5}{5} i

Solution

x_{1} = - \frac{2 5}{5} i, x_{2} = \frac{2 5}{5} i

Alternative Form

x_{1} \approx - 0.894427 i, x_{2} \approx 0.894427 i

Show Solution