If (p+2)(2q-1)=2pq-10 and (p-2)(2q-1)=2pq-10, then what is pq equal to?

Explanation

Equating the two expressions gives (p+2)(2q-1) = (p-2)(2q-1), which simplifies to 4(2q-1) = 0, so q = \frac{1}{2}. Substituting q into the first equation yields 0 = p - 10, so p = 10. Thus, pq = 10 \times \frac{1}{2} = 5.

Related questions on Algebra

• If p + q + r = 0, then what is z^{\frac{p^2}{qr}} \times z^{\frac{q^2}{rp}} \times z^{\frac{r^2}{pq}} equal to ?
• What is the value of k for which (k^2 - 5k + 4)x^2 + (k^2 - 3k - 4)x + (k^2 - 4k) = 0 is an identity ?
• If \frac{a^2}{b^2 + c^2} = \frac{b^2}{c^2 + a^2} = \frac{c^2}{a^2 + b^2}, then what is the value of a^4 + b^4 + c^4 equal to ?
• If \frac{1}{x} = \frac{1}{p} + \frac{1}{q}, then what is \frac{pq}{p^2 - q^2}\left(\frac{x + p}{x - p} - \frac{x + q}{x - q}\right) equa...
• If (x - 5) is the HCF of x^2 - x - p and x^2 - qx - 10, then what is the value of (p + q) ?