Solve 12-20 f^4 - ScanMath

Question

Factor the expression

4 (3 - 5 f^{4})

Evaluate

12 - 20 f^{4}

Solution

4 (3 - 5 f^{4})

Show Solution

f_{1} = - \frac{4 375}{5}, f_{2} = \frac{4 375}{5}

Alternative Form

f_{1} \approx - 0.880112, f_{2} \approx 0.880112

Evaluate

12 - 20 f^{4}

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

12 - 20 f^{4} = 0

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

- 20 f^{4} = 0 - 12

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

- 20 f^{4} = - 12

Change the signs on both sides of the equation

20 f^{4} = 12

Divide both sides

\frac{20 f ^{4}}{20} = \frac{12}{20}

Divide the numbers

f^{4} = \frac{12}{20}

Cancel out the common factor 4

f^{4} = \frac{3}{5}

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

f = \pm 4 \frac{3}{5}

Simplify the expression

More Steps

Evaluate

4 \frac{3}{5}

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

\frac{4 3}{4 5}

Multiply by the Conjugate

\frac{4 3 \times 4 5 ^{3}}{4 5 \times 4 5 ^{3}}

Simplify

\frac{4 3 \times 4 125}{4 5 \times 4 5 ^{3}}

Multiply the numbers

More Steps

Evaluate

43 \times 4125

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

4 3 \times 125

Calculate the product

4375

\frac{4 375}{4 5 \times 4 5 ^{3}}

Multiply the numbers

More Steps

Evaluate

45 \times 4 5^{3}

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

4 5 \times 5^{3}

Calculate the product

4 5^{4}

Reduce the index of the radical and exponent with 4

5

\frac{4 375}{5}

f = \pm \frac{4 375}{5}

Separate the equation into 2 possible cases

f = \frac{4 375}{5} f = - \frac{4 375}{5}

Solution

f_{1} = - \frac{4 375}{5}, f_{2} = \frac{4 375}{5}

Alternative Form

f_{1} \approx - 0.880112, f_{2} \approx 0.880112

Show Solution