Solve 28-70 f^2 - ScanMath

Question

Factor the expression

14 (2 - 5 f^{2})

Evaluate

28 - 70 f^{2}

Solution

14 (2 - 5 f^{2})

Show Solution

f_{1} = - \frac{10}{5}, f_{2} = \frac{10}{5}

Alternative Form

f_{1} \approx - 0.632456, f_{2} \approx 0.632456

Evaluate

28 - 70 f^{2}

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

28 - 70 f^{2} = 0

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

- 70 f^{2} = 0 - 28

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

- 70 f^{2} = - 28

Change the signs on both sides of the equation

70 f^{2} = 28

Divide both sides

\frac{70 f ^{2}}{70} = \frac{28}{70}

Divide the numbers

f^{2} = \frac{28}{70}

Cancel out the common factor 14

f^{2} = \frac{2}{5}

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

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

Simplify the expression

More Steps

Evaluate

\frac{2}{5}

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

\frac{2}{5}

Multiply by the Conjugate

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

Multiply the numbers

More Steps

Evaluate

2 \times 5

The product of roots with the same index is equal to the root of the product

2 \times 5

Calculate the product

10

\frac{10}{5 \times 5}

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

\frac{10}{5}

f = \pm \frac{10}{5}

Separate the equation into 2 possible cases

f = \frac{10}{5} f = - \frac{10}{5}

Solution

f_{1} = - \frac{10}{5}, f_{2} = \frac{10}{5}

Alternative Form

f_{1} \approx - 0.632456, f_{2} \approx 0.632456

Show Solution