Solve -2(-2r^24r-3)

Question

Simplify the expression

16 r^{3} + 6

Evaluate

- 2 (- 2 r^{2} \times 4 r - 3)

Multiply

More Steps

Evaluate

- 2 r^{2} \times 4 r

Multiply the terms

- 8 r^{2} \times r

Multiply the terms with the same base by adding their exponents

- 8 r^{2 + 1}

Add the numbers

- 8 r^{3}

- 2 (- 8 r^{3} - 3)

Apply the distributive property

- 2 (- 8 r^{3}) - (- 2 \times 3)

Multiply the numbers

More Steps

Evaluate

- 2 (- 8)

Multiplying or dividing an even number of negative terms equals a positive

2 \times 8

Multiply the numbers

16

16 r^{3} - (- 2 \times 3)

Multiply the numbers

16 r^{3} - (- 6)

Solution

16 r^{3} + 6

Show Solution

r = - \frac{3 3}{2}

Alternative Form

r \approx - 0.721125

Evaluate

- 2 (- 2 r^{2} \times 4 r - 3)

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

- 2 (- 2 r^{2} \times 4 r - 3) = 0

Multiply

More Steps

Multiply the terms

- 2 r^{2} \times 4 r

Multiply the terms

- 8 r^{2} \times r

Multiply the terms with the same base by adding their exponents

- 8 r^{2 + 1}

Add the numbers

- 8 r^{3}

- 2 (- 8 r^{3} - 3) = 0

Change the sign

2 (- 8 r^{3} - 3) = 0

Rewrite the expression

- 8 r^{3} - 3 = 0

Move the constant to the right side

- 8 r^{3} = 3

Change the signs on both sides of the equation

8 r^{3} = - 3

Divide both sides

\frac{8 r ^{3}}{8} = \frac{- 3}{8}

Divide the numbers

r^{3} = \frac{- 3}{8}

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

r^{3} = - \frac{3}{8}

Take the 3 -th root on both sides of the equation

3 r^{3} = 3 - \frac{3}{8}

Calculate

r = 3 - \frac{3}{8}

Solution

More Steps

Evaluate

3 - \frac{3}{8}

An odd root of a negative radicand is always a negative

- 3 \frac{3}{8}

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

- \frac{3 3}{3 8}

Simplify the radical expression

More Steps

Evaluate

38

Write the number in exponential form with the base of 2

3 2^{3}

Reduce the index of the radical and exponent with 3

2

- \frac{3 3}{2}

r = - \frac{3 3}{2}

Alternative Form

r \approx - 0.721125

Show Solution