Question 127385
Solve for xy:
{{{x^2y^2-17xy+60}}} Can you see this as a quadratic equation in xy?
{{{(xy)^2-17(xy)+60}}} This can be factored:
{{{(xy-5)(xy-12)}}} Applying the zero products principle, we get:
{{{xy-5 = 0}}} or {{{xy-12 = 0}}} so that...
{{{xy = 5}}} or {{{xy = 12}}}
You expected to get:
{{{xy = 3}}} and {{{xy = 20}}} but your equation would have to be:
{{{x^2y^2-23xy+60}}} which factors into...
{{{(xy-3)(xy-20)}}} thus giving you...
{{{xy = 3}}} or {{{xy = 20}}} or... to get {{{xy = -3}}}, {{{xy = 20}}}, your equation should be:
{{{x^2y^2-17xy-60}}} which factors into...
{{{(xy+3)(xy-20)}}} thus giving you...
{{{xy = -3}}} or {{{xy = 20}}}