FACTORISE..16(x+y)2-81(x-2y)2
16(x+y)2 - 81(x-2y)2
= {4(x+y)}2 - {9(x-2y)}2
= {4x+4y}2 - {9x- 18y}2
= {4x+4y - 9x +18y}{4x+4y +9x - 18y}
= {-5x + 22y}{9x - 14y}
= {4(x+y)}2 - {9(x-2y)}2
= {4x+4y}2 - {9x- 18y}2
= {4x+4y - 9x +18y}{4x+4y +9x - 18y}
= {-5x + 22y}{9x - 14y}