Solve 8x^2-6x-5 - ScanMath

Question

Factor the expression

(2 x + 1) (4 x - 5)

Evaluate

8 x^{2} - 6 x - 5

Rewrite the expression

8 x^{2} + (- 10 + 4) x - 5

Calculate

8 x^{2} - 10 x + 4 x - 5

Rewrite the expression

2 x \times 4 x - 2 x \times 5 + 4 x - 5

Factor out 2 x from the expression

2 x (4 x - 5) + 4 x - 5

Solution

(2 x + 1) (4 x - 5)

Show Solution

x_{1} = - \frac{1}{2}, x_{2} = \frac{5}{4}

Alternative Form

x_{1} = - 0.5, x_{2} = 1.25

Evaluate

8 x^{2} - 6 x - 5

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

8 x^{2} - 6 x - 5 = 0

Factor the expression

More Steps

Evaluate

8 x^{2} - 6 x - 5

Rewrite the expression

8 x^{2} + (- 10 + 4) x - 5

Calculate

8 x^{2} - 10 x + 4 x - 5

Rewrite the expression

2 x \times 4 x - 2 x \times 5 + 4 x - 5

Factor out 2 x from the expression

2 x (4 x - 5) + 4 x - 5

Factor out 4 x - 5 from the expression

(2 x + 1) (4 x - 5)

(2 x + 1) (4 x - 5) = 0

When the product of factors equals 0,at least one factor is 0

2 x + 1 = 0 4 x - 5 = 0

Solve the equation for x

More Steps

Evaluate

2 x + 1 = 0

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

2 x = 0 - 1

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

2 x = - 1

Divide both sides

\frac{2 x}{2} = \frac{- 1}{2}

Divide the numbers

x = \frac{- 1}{2}

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

x = - \frac{1}{2}

x = - \frac{1}{2} 4 x - 5 = 0

Solve the equation for x

More Steps

Evaluate

4 x - 5 = 0

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

4 x = 0 + 5

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

4 x = 5

Divide both sides

\frac{4 x}{4} = \frac{5}{4}

Divide the numbers

x = \frac{5}{4}

x = - \frac{1}{2} x = \frac{5}{4}

Solution

x_{1} = - \frac{1}{2}, x_{2} = \frac{5}{4}

Alternative Form

x_{1} = - 0.5, x_{2} = 1.25

Show Solution