Question

help me with this ques.

Answer 1

as (2x+3y)=12 & xy=6 given
so x=6/y
Now, put this value in (2x+3y)=12
so,
2(6/y) +3y=12
12/y + 3y =12
after taking l.c.m
12 + 3y^2 =12y
3y^2-12y+12=0 ........
now solve this factor

3(y^2-4y +4)=0
y^2-4y+4=0

factors are y=(2,2)
now put {y=2} in {x=6/y}

we get x=3

so our value of x is 3 &y is 2
put this in 4x^2+9y^2

4(3)^2+9(2)^2=36+36=72

so 4x^2 +9y^2=72