26.
|4x - 9| = 19 ⇔ 4x - 9 = 19 or 4x - 9 = -19 |add 9 to both sides
4x = 28 or 4x = -10 |divide both sides by 4
x = 7 or x = -2.5
Answer: (C) 7.
27.
m = (p/q)^4 = p^4/q^4; n = (q/p)^(-2) = q^(-2)/p^(-2)
m/n = (p^4/q^4)/[q^(-2)/p^(-2)] = (p^4/q^4) · [p^(-2)/q^(-2)]
= p^(4-2)/q^(4-2) = p^2/q^2 = (p/q)^2
Answer: (C) (p/q)^2.
