Solve 2m^2-7m-9 - ScanMath

Question

Factor the expression

(m + 1) (2 m - 9)

Evaluate

2 m^{2} - 7 m - 9

Rewrite the expression

2 m^{2} + (- 9 + 2) m - 9

Calculate

2 m^{2} - 9 m + 2 m - 9

Rewrite the expression

m \times 2 m - m \times 9 + 2 m - 9

Factor out m from the expression

m (2 m - 9) + 2 m - 9

Solution

(m + 1) (2 m - 9)

Show Solution

m_{1} = - 1, m_{2} = \frac{9}{2}

Alternative Form

m_{1} = - 1, m_{2} = 4.5

Evaluate

2 m^{2} - 7 m - 9

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

2 m^{2} - 7 m - 9 = 0

Factor the expression

More Steps

Evaluate

2 m^{2} - 7 m - 9

Rewrite the expression

2 m^{2} + (- 9 + 2) m - 9

Calculate

2 m^{2} - 9 m + 2 m - 9

Rewrite the expression

m \times 2 m - m \times 9 + 2 m - 9

Factor out m from the expression

m (2 m - 9) + 2 m - 9

Factor out 2 m - 9 from the expression

(m + 1) (2 m - 9)

(m + 1) (2 m - 9) = 0

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

m + 1 = 0 2 m - 9 = 0

Solve the equation for m

More Steps

Evaluate

m + 1 = 0

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

m = 0 - 1

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

m = - 1

m = - 1 2 m - 9 = 0

Solve the equation for m

More Steps

Evaluate

2 m - 9 = 0

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

2 m = 0 + 9

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

2 m = 9

Divide both sides

\frac{2 m}{2} = \frac{9}{2}

Divide the numbers

m = \frac{9}{2}

m = - 1 m = \frac{9}{2}

Solution

m_{1} = - 1, m_{2} = \frac{9}{2}

Alternative Form

m_{1} = - 1, m_{2} = 4.5

Show Solution