Find the value of the expression `(81 x^(2) + 16 y^(2) - 72 xy)` when `x = (2)/(3)` and `y = (3)/(4)`

Find the value of the expression (36x^(2) + 25y^(2) - 60 xy) , when x = (2)/(3) and y = (1)/(5)

find the value of the expression (64x^(2) + 81y^(2) + 144 xy) when x = 11 and y = (4)/(3)

Find the value of the expression 25 x^(2) + 9y^(2) + 30 xy . When x = 8 and y = 10.

The maximum value of the expression (3y^(2)-4xy)/(x^(2)+y^(2)) is

Factoris the expression. x ^(2) y ^(2) + x ^(2) y ^(3) - xy ^(4) + xy

When x = (1)/(9) and y = (-3)/(4), then the value of the expression 81 x ^(2) + 16 y ^(2)- 72 xy is

Evaluate the expression 16/x + 2y for x = 8 and y=3 .

12xy (9x ^ (2) -16y ^ (2)) -: 4xy (3x + 4y)

Find the values of the following expressions: 16x^(2)+24+9, when x=(7)/(4)64x^(2)+81y^(2)+144xy, when x=11 and y=(4)/(3)81x^(2)+16y^(2)-72xy, when x=(2)/(3) and y=(3)/(4)