Question

Factorise the following?
x²+9y²-25m²-16n²+6xy+40mn

Answer 1

$x^2 + 9y^2 - 25m^2 -16n^2+6xy+40mn \\ \\ x^2+9y^2+6xy - (16n^2-40mn+25m^2) \\ \\ (x+3y)^2 - (4n-5m)^2 \\ \\ (x+3y+4n-5m)(x+3y-4n+5m)\ ,\ \ \ \ As\ a^2 - b^2 = (a+b)(a-b)$

Answer 2

Step-by-step explanation:

x²+9y²-25m²-16n²+

x²+9y²+6xy-(16n²-4

(x+3y)²-(4n-

(x+3y+4n-5m) (x+3y=-4n+5m