Question

Substitute the values for a, b, and c into b2 – 4ac to determine the discriminant. Which quadratic equations will have two real number solutions? (The related quadratic function will have two x-intercepts.) Check all that apply. 0 = 2x2 – 7x – 9 0 = x2 – 4x + 4 0 = 4x2 – 3x – 1 0 = x2 – 2x – 8 0 = 3x2 + 5x + 3

Answer 1

Step-by-step explanation

Prerequisites:

You need to know:

`b^2 - 4ac = 0 \Rightarrow 1 solution`

`b^2 - 4ac > 0 \Rightarrow 2 solutions`

`b^2 - 4ac < 0 \Rightarrow No\ real\ solutions`

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`2x^2-7x-9 = 0`

`b^2 - 4ac`

`-7^2 - 4(2)(-9) = 121`

2 Solutions

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`x^2-4x+4 = 0`

`b^2 - 4ac`

`-4^2 - 4(1)(4) = 0`

1 Solution

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`4x^2-3x-1 = 0`

`b^2 - 4ac`

`-3^2 - 4(4)(-1) = 25`

2 Solutions

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`x^2-2x-8 = 0`

`b^2 - 4ac`

`-2^2 - 4(1)(-8) = 36`

2 Solutions

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`3x^2+5x+3 = 0`

`b^2 - 4ac`

`5^2 - 4(3)(3) = -11`

No Solutions

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Answer 2

A, C, D

Explanation:

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