Solve 4x^2 9x-2 - ScanMath

Question

Simplify the expression

36 x^{3} - 2

Evaluate

4 x^{2} \times 9 x - 2

Solution

More Steps

Evaluate

4 x^{2} \times 9 x

Multiply the terms

36 x^{2} \times x

Multiply the terms with the same base by adding their exponents

36 x^{2 + 1}

Add the numbers

36 x^{3}

36 x^{3} - 2

Show Solution

Factor the expression

2 (18 x^{3} - 1)

Evaluate

4 x^{2} \times 9 x - 2

Multiply

More Steps

Evaluate

4 x^{2} \times 9 x

Multiply the terms

36 x^{2} \times x

Multiply the terms with the same base by adding their exponents

36 x^{2 + 1}

Add the numbers

36 x^{3}

36 x^{3} - 2

Solution

2 (18 x^{3} - 1)

Show Solution

Find the roots

x = \frac{3 12}{6}

Alternative Form

x \approx 0.381571

Evaluate

4 x^{2} \times 9 x - 2

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

4 x^{2} \times 9 x - 2 = 0

Multiply

More Steps

Multiply the terms

4 x^{2} \times 9 x

Multiply the terms

36 x^{2} \times x

Multiply the terms with the same base by adding their exponents

36 x^{2 + 1}

Add the numbers

36 x^{3}

36 x^{3} - 2 = 0

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

36 x^{3} = 0 + 2

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

36 x^{3} = 2

Divide both sides

\frac{36 x ^{3}}{36} = \frac{2}{36}

Divide the numbers

x^{3} = \frac{2}{36}

Cancel out the common factor 2

x^{3} = \frac{1}{18}

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

3 x^{3} = 3 \frac{1}{18}

Calculate

x = 3 \frac{1}{18}

Solution

More Steps

Evaluate

3 \frac{1}{18}

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

\frac{3 1}{3 18}

Simplify the radical expression

\frac{1}{3 18}

Multiply by the Conjugate

\frac{3 1 8 ^{2}}{3 18 \times 3 1 8 ^{2}}

Simplify

\frac{3 3 12}{3 18 \times 3 1 8 ^{2}}

Multiply the numbers

More Steps

Evaluate

318 \times 3 1 8^{2}

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

3 18 \times 1 8^{2}

Calculate the product

3 1 8^{3}

Reduce the index of the radical and exponent with 3

18

\frac{3 3 12}{18}

Cancel out the common factor 3

\frac{3 12}{6}

x = \frac{3 12}{6}

Alternative Form

x \approx 0.381571

Show Solution