Solve 2s^2-15s-8=0

Question

Solve the quadratic equation

Solve by factoring

Solve using the quadratic formula

Solve by completing the square

s_{1} = - \frac{1}{2}, s_{2} = 8

Alternative Form

s_{1} = - 0.5, s_{2} = 8

Evaluate

2 s^{2} - 15 s - 8 = 0

Factor the expression

More Steps

Evaluate

2 s^{2} - 15 s - 8

Rewrite the expression

2 s^{2} + (1 - 16) s - 8

Calculate

2 s^{2} + s - 16 s - 8

Rewrite the expression

s \times 2 s + s - 8 \times 2 s - 8

Factor out s from the expression

s (2 s + 1) - 8 \times 2 s - 8

Factor out - 8 from the expression

s (2 s + 1) - 8 (2 s + 1)

Factor out 2 s + 1 from the expression

(s - 8) (2 s + 1)

(s - 8) (2 s + 1) = 0

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

s - 8 = 0 2 s + 1 = 0

Solve the equation for s

More Steps

Evaluate

s - 8 = 0

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

s = 0 + 8

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

s = 8

s = 8 2 s + 1 = 0

Solve the equation for s

More Steps

Evaluate

2 s + 1 = 0

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

2 s = 0 - 1

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

2 s = - 1

Divide both sides

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

Divide the numbers

s = \frac{- 1}{2}

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

s = - \frac{1}{2}

s = 8 s = - \frac{1}{2}

Solution

s_{1} = - \frac{1}{2}, s_{2} = 8

Alternative Form

s_{1} = - 0.5, s_{2} = 8

Show Solution