Solve 1b^3021-3 - ScanMath

Question

Simplify the expression

21 b^{3} - 3

Evaluate

1 \times b^{3} \times 21 - 3

Solution

More Steps

Evaluate

1 \times b^{3} \times 21

Rewrite the expression

b^{3} \times 21

Use the commutative property to reorder the terms

21 b^{3}

21 b^{3} - 3

Show Solution

3 (7 b^{3} - 1)

Evaluate

1 \times b^{3} \times 21 - 3

Multiply the terms

More Steps

Evaluate

1 \times b^{3} \times 21

Rewrite the expression

b^{3} \times 21

Use the commutative property to reorder the terms

21 b^{3}

21 b^{3} - 3

Solution

3 (7 b^{3} - 1)

Show Solution

b = \frac{3 49}{7}

Alternative Form

b \approx 0.522758

Evaluate

1 \times b^{3} \times 21 - 3

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

1 \times b^{3} \times 21 - 3 = 0

Multiply the terms

More Steps

Multiply the terms

1 \times b^{3} \times 21

Rewrite the expression

b^{3} \times 21

Use the commutative property to reorder the terms

21 b^{3}

21 b^{3} - 3 = 0

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

21 b^{3} = 0 + 3

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

21 b^{3} = 3

Divide both sides

\frac{21 b ^{3}}{21} = \frac{3}{21}

Divide the numbers

b^{3} = \frac{3}{21}

Cancel out the common factor 3

b^{3} = \frac{1}{7}

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

3 b^{3} = 3 \frac{1}{7}

Calculate

b = 3 \frac{1}{7}

Solution

More Steps

Evaluate

3 \frac{1}{7}

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

\frac{3 1}{3 7}

Simplify the radical expression

\frac{1}{3 7}

Multiply by the Conjugate

\frac{3 7 ^{2}}{3 7 \times 3 7 ^{2}}

Simplify

\frac{3 49}{3 7 \times 3 7 ^{2}}

Multiply the numbers

More Steps

Evaluate

37 \times 3 7^{2}

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

3 7 \times 7^{2}

Calculate the product

3 7^{3}

Reduce the index of the radical and exponent with 3

7

\frac{3 49}{7}

b = \frac{3 49}{7}

Alternative Form

b \approx 0.522758

Show Solution