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Need an answer for question 7 HURRY PLEASE 20 POINTS

Need an answer for question 7 HURRY PLEASE 20 POINTS-example-1

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Answer:

2x^2 = 6x - 5.

-x^2 - 10x = 34.

These have only complex roots/

Explanation:

3x^2 - 5x = -8

3x^2 - 5x + 8 = 0

There are complex roots if the discriminant 9b^2 - 4ac) is negative.

Here the discriminant D = (-5)^2 - 4*-5*8 = 25 + 160

This is positive so the roots are real.

2x^2 = 6x - 5

2x^2 - 6x + 5 = 0

D = (-6)^2 - 4*2*5 = 36 - 40 = -4

So this has no real roots only complex ones.

12x = 9x^2 + 4

9x^2 - 12x + 4 = 0

D = (-12)^2 - 4*9 * 4 = 144 - 144 = 0.

- Real roots.

-x^2 - 10x = 34

x^2 + 10x + 34 = 0

D = (10)^2 - 4*1*34 = 100 - 136 = -36.

No real roots = only complex roots.

User Plonetheus
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