Question

if X square + xy + X =12 and y square + xy + Y = 18 then find the value of x + Y​

Answer 1

Answer:

5 (or) -6

Step-by-step explanation:

add two equations

x²+xy+x+y²+xy+y=12+18

(x+y)²+x+y=30

let x+y=z

z²+z-30=0

z²-5z+6z-30=0

z(z-5)+6(z-5)=0

(z+6)(z-5)=0

z=-6, z=5

z=x+y

x+y= -6 (or) 5