If x=2+3,xy=1, then find x2-x+y2-y.
−√3
√3
−√2
−2
-2
Finding x2-x+y2-y
Given that x=2+3,xy=1
x2-x+y2-y
=x2-x+y2-y=x2-x+xy2x-1(∵xy=1⇔y=1x)=x2-x+12x-1=2+32-(2+3)+12(2+3)-1=2+32-2-3+12×2+23-1=2+3-3+13+23=-6-73-6+333+23(addingboththefraction)=-12+6333+23=-12+6333+6=-6(2+3)3(2+3)=-63=-2
Hence, the correct answer is (D)-2
Evaluate the following expression forx=-1,y=-2,z=3
xy+yz+zx
Solve the following system of linear equations forxandy
xa+yb=2;bx-ay=a+b