Question 126344
{{{(x+y)^2=17}}} Start with the first equation



{{{x^2+2xy+y^2=17}}} Foil the left side


Notice how the second equation is {{{xy=3}}} and the 2nd step has an "2xy" term in it. So let's multiply both sides of {{{xy=3}}} by 2


{{{2*xy=2*3}}}


{{{2xy=6}}}




So this means we can replace the "2xy" term in {{{x^2+2xy+y^2=17}}} with 6



{{{x^2+6+y^2=17}}} Replace {{{2x}}} with 6



{{{x^2+cross(6-6)+y^2=17-6}}} Subtract 6 from both sides



{{{x^2+y^2=11}}} Combine like terms




Answer:


So our answer is {{{x^2+y^2=11}}} which means that the answer is D)