[" 2.If "x=3" and "y=-1," find the values of each of the following using in identity: "],[[" (i) "(9y^(2)-4x^(2))(81y^(4)+36x^(2)y^(2)+16x^(4)),],[" (ii) "((3)/(x)-(x)/(3))((x^(2))/(9)+(9)/(x^(2))+1)," (iii) "((x)/(7)+(y)/(3))((x^(2))/(49)+(y^(2))/(9)-(xy)/(21))],[" (iv) "((x)/(4)-(y)/(3))((x^(2))/(16)+(xy)/(12)+(y^(2))/(9))," (v) "((5)/(x)+5x)((25)/(x^(2))-25+25x^(2))],[" (fat "b=10" and "ab=16," find the value of "a^(2)-ab+b^(2)" and "a^(2)+ab+b^(2)]],[" If "a+b=8" and "ab=6," find the value of "a^(3)+b^(3)]