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X2 - 4X - 11 = 8

subtracting 8 from each side

X2 - 4X - 19 = 0

I do not even try to factor these, but I use the quadratic formula.

X = - b (+/-) sqrt(b2 - 4ac)/2a

a = 1

b = - 4

c = - 19

X = - (- 4) (+/-) sqrt[(- 4)2 - 4(1)(- 19)]/2(1)

X = 4 (+/-) sqrt(16 + 76)/2

X = 4 (+/-) sqrt(92)/2

X = 4 (+/-) sqrt(22 * 23)/2

X = [4 (+/-) 2sqrt(23)]/2

-----------------------------------------exact answer which you can clean up by numerator/denominator eleimination and you can estimate the X intercepts also.

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13y ago

What else can I help you with?