Question

para xy =9a e x² =y²=181, encontre o valor de (3x-3y)²=

Answer 1

(3x-3y).(3x-3y)=
9x²-9xy-9xy+9y²=
         9
x²-xy-xy+y²=
181-9a-9a+181=
18a=362
a=362
    18
a=20