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Using the quadratic formula to solve 2x^2 = 4x – 7, what are the values of x?

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Answer:

Explanation:

To use the quadratic formula, we must write the quadratic in standard form, viz:

2x^2 - 4x + 7 = 0

Start by calculating the discriminant. That's b^2 - 4(a)(c). Here,

a = 2, b = -4 and c = 7, and so the discriminant for this particular problem is

(-4)^2 - 4(2)(7), or 16 - 56, or 40.

Recall that a positive discriminant indicates two real, unequal roots.

Now we write out the whole quadratic formula, with the appropriate constants inserted (see above):

-(-4) ± √40 4 ± (√4)(√10) 4 ± 2√10

x = --------------------- = ---------------------- = ---------------

2(2) 4 4

2 ± √10

which reduces to x = --------------

2

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