Factor -11x² - 49x

Factor -11x² - 49x - 54

Here we will show you how to factor the quadratic function -11x² - 49x - 54 using the box method. In other words, we will show you how to factor negative 11x squared minus 49x minus 54 (-11x^2 - 49x - 54) using the box method. It is a 5-step process:

Step 1: The standard form of a quadratic equation is ax² + bx + c. In this equation, a is negative. Therefore, we need to start by setting aside the negative (-). We do this by flipping the signs in the equation to get 11x² + 49x + 54. Now we can label the different parts of our equation, like this:

a = 11
b = 49
c = 54

Step 2: Next, we need to draw a box and divide it into four squares:

2	22x	54
x	11x²	27x
	11x	27

We put 11x² (a) in the bottom left square and 54 (c) in the top right square, like this:

2	22x	54
x	11x²	27x
	11x	27

Step 3: In order to fill in the other two squares, we need to do some math. We have to find two numbers that multiply together to give us the product of 11 times 54 (a × c), and add together to equal 49 (b).

More specifically, 11 times 54 is 594. Therefore, we need to find the two numbers that multiply to equal 594, and add to equal 49.

? × ? = 594
? + ? = 49

After looking at this problem, we can see that the two numbers that multiply together to equal 594, and add together to equal 49, are 22 and 27, as illustrated here:

22 × 27 = 594
22 + 27 = 49

Now, we can fill in the last two squares in our box with 22x and 27x. Place 22x in the upper left square, and place 27x in the lower right square.

2	22x	54
x	11x²	27x
	11x	27

Step 4: Next, we need to find four final numbers to finish factoring our equation. We can see that our box is a 2 x 2 table made up of rows and columns.

Our goal is to find the numbers that, when multiplied together, result in the products in each square. We can do this by finding the greatest common factor in each row.

Let’s look at the top row. We have the terms 22x and 54. The greatest common factor of 22x and 54 is 2. Therefore, we write 2 to the left of the top row. You can see it here in the color green:

2	22x	54
x	11x²	27x
	11x	27

Next, let’s look at the bottom row. We have the terms 11x² and 27x. The greatest common factor of 11x² and 27x is x. Therefore, we write x to the left of the bottom row. You can see it here in the color blue:

2	22x	54
x	11x²	27x
	11x	27

To find the values below the table, we first divide 11x² by x (labeled in blue). This gives us 11x.

11x² ÷ x = 11x

You can see this value colored in orange below:

2	22x	54
x	11x²	27x
	11x	27

Next, we divide 27x by x (labeled in blue). This gives us 27.

27x ÷ x = 27

You can see this value colored in purple below:

2	22x	54
x	11x²	27x
	11x	27

Step 5: Now we have all of the information we need to finish factoring the equation. The values outside of the box are used to factor -11x² - 49x - 54. You simply put the values on the left in one set of parentheses, and the values below in another set of parentheses, to get:

(x + 2)(11x + 27)

In our original quadratic equation, -11x² - 49x - 54, a is negative. Therefore, we need to add a negative (-) sign before our two sets of parentheses, like this:

-(x + 2)(11x + 27)

That’s it! Now you know how to factor the equation -11x² - 49x - 54.

Factoring Quadratics
Go here if you want to learn how to factor another quadratic function.

Factor -11x² - 49x - 48
Here is the next quadratic function on our list that we have factored for you.