FSQE - Factor When a is Not 1 (Lesson)
Factor When a is Not 1
When the leading coefficient is not 1, we have to work a little harder to factor quadratics, because we have to take into account the value of a.
Here is an example below:
2x2 + x - 6
There are quite a few methods to factor this quadratic, one of those methods is guess and check - but sometimes this can take too long. So let's look at the method called split the middle.
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2x2 + x - 6 |
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1. Multiply ac |
2(-6) = -12 |
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2. Find two numbers that multiply to make ac and add up to b |
4 - 3 = 1 4(-3) = -12 |
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3. Replace the b term with these two values |
2x2 + 4x - 3x - 6 |
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4. Group the first two terms and the second two terms *always put a plus sign between your groups! |
(2x2 + 4x) + (-3x - 6) |
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5. Factor the GCF from each of the terms |
2x(x +2) -3(x +2) |
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6. Factor (x + 2) from each term |
(x + 2)(2x - 3) |
Watch this video to see a few more examples:
Factor when a is not 1 Practice
- 3p2 - 2p - 5
- 2x2 + 11x + 5
- 4a2 - 15a - 25
- 15n2 - 27n - 6
TO VIEW THE SOLUTIONS ONCE YOU HAVE PRACTICED, CLICK HERE. Links to an external site.
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