Question

if x - y = 4, xy = 12 , then find x² + y²​

Answer 1

40 is the ryt answer

given, x-y=4 -eq.1

xy=12 -eq.2

so, x=4+y -eq3

put the value of x in the form of y in eq.2

so we get, (4+y)y=12

4y+y²=12

y²+4y-12=0

y²+(6-2)y-12=0 (by factors of 12 )

y²+6y-2y-12=0

y(y+6)-2(y+6)=0

(y+6)(y-2)=0

y=-6,2

put the value of y in eq3

we get x=-2,6

now we have to find x²+y²

we have values of x and y so we easily find x²+y²

which is (-2)²+(-6)² or 6²+2² =40 answer