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}, x_{2} = \frac{2 5}{5}

Alternative Form

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

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

Divide both sides

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

Divide the numbers

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}

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

\frac{4}{5}

Simplify the radical expression

More Steps

Evaluate

4

Write the number in exponential form with the base of 2

2^{2}

Reduce the index of the radical and exponent with 2

2

\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}

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

Separate the equation into 2 possible cases

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

Solution

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

Alternative Form

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

Show Solution