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Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.