Question

please solve the 40th sum.

Answer 1

15(x-2y)²-8(x-2y)-16

let (x-2y)=a

=15a²-8a-16
=15a²-20a+12a-16
=5a(3a-4)+4(3a-4)
=(5a+4)(3a-2)
=(5(x-2y)+4)(3(x-2y)-4)
=(5x-10y+4)(3x-6y-4) is the ans.

Answer 2

please see the attachment.