Solve 2x^2+17x+21

Question

Factor the expression

(x + 7) (2 x + 3)

Evaluate

2 x^{2} + 17 x + 21

Rewrite the expression

2 x^{2} + (3 + 14) x + 21

Calculate

2 x^{2} + 3 x + 14 x + 21

Rewrite the expression

x \times 2 x + x \times 3 + 7 \times 2 x + 7 \times 3

Factor out x from the expression

x (2 x + 3) + 7 \times 2 x + 7 \times 3

Factor out 7 from the expression

x (2 x + 3) + 7 (2 x + 3)

Solution

(x + 7) (2 x + 3)

Show Solution

x_{1} = - 7, x_{2} = - \frac{3}{2}

Alternative Form

x_{1} = - 7, x_{2} = - 1.5

Evaluate

2 x^{2} + 17 x + 21

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

2 x^{2} + 17 x + 21 = 0

Factor the expression

More Steps

Evaluate

2 x^{2} + 17 x + 21

Rewrite the expression

2 x^{2} + (3 + 14) x + 21

Calculate

2 x^{2} + 3 x + 14 x + 21

Rewrite the expression

x \times 2 x + x \times 3 + 7 \times 2 x + 7 \times 3

Factor out x from the expression

x (2 x + 3) + 7 \times 2 x + 7 \times 3

Factor out 7 from the expression

x (2 x + 3) + 7 (2 x + 3)

Factor out 2 x + 3 from the expression

(x + 7) (2 x + 3)

(x + 7) (2 x + 3) = 0

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

x + 7 = 0 2 x + 3 = 0

Solve the equation for x

More Steps

Evaluate

x + 7 = 0

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

x = 0 - 7

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

x = - 7

x = - 7 2 x + 3 = 0

Solve the equation for x

More Steps

Evaluate

2 x + 3 = 0

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

2 x = 0 - 3

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

2 x = - 3

Divide both sides

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

Divide the numbers

x = \frac{- 3}{2}

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

x = - \frac{3}{2}

x = - 7 x = - \frac{3}{2}

Solution

x_{1} = - 7, x_{2} = - \frac{3}{2}

Alternative Form

x_{1} = - 7, x_{2} = - 1.5

Show Solution