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Factor completely 4a^2 - 8a - 5

User Chillie
by
4.5k points

1 Answer

4 votes

Answer:

Explanation:

Use the quadratic formula first; find the roots, and then write the factors based upon the roots. Here, a = 4, b = -8 and c = -5. Thus, the discriminant b^2 - 4ac is (-8)^2 - 4(4)(-5), or 64 + 80, or 144.

Thus, we have:

-(-8) ± √144 8 ± 12

x = --------------------- = -------------- = 5/2 and x = -1/2

2(4) 8

If x = 5/2 is a root, then (2x - 5) is a factor.

If x = -1/2 is a root, then (2x + 1) is the other factor.

or

User Hitesh
by
5.3k points
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