KVPY2015MathematicsQuadratic Equation
The number of ordered pairs (x, y) of real numbers that satisfy the simultaneous equations. x+y²=x²+y=12 is
Options
- A0
- B1
- C2
- D4
Correct answer
D. 4
Step-by-step solution
array l x + y ²= x ²+ y =12 x + y ²= x ²+ y x-y=x²-y² x=y, x + y =1 when x = y x ²+ x =12 x ²+ x -12=0 x ²+4 x -3 x -12=0 ( x +4)( x -3)=0 x =-4,3 (3,3)(-4,-4) When y =1- x x +(1- x )²=12 x ²- x -11=0 x= 1 1+44 2 array So four pair.