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Consider the equation x^2-7x-8=0 and describe it's roots​

1 Answer

21 votes
21 votes

Answer:

there are two different, real roots.

Explanation:

The coefficients of this quadratic are {1, -7, -8}. Let's find the discriminant, b^2 - 4ac. In this case a = 1, b = -7 and c = -8 and so the discriminant value is

(-7)^2 - 4(1)(-8), or 49 + 32, or 81.

Because the discriminant is positive, we know immediately that there are two different, real roots.

We are not asked to find the roots, but let's do it anyway:

-(-7) ± √81

x = ------------------ => x = 8 and x = -2 (which are real and different from

2 one another).

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