Question

(2.5p-1.5q square by -1.5p minus 2.5q square

Answer 1

As a2-b2=(a-b) (a+b)
so, (2.5p-1.5q)2-(1.5p-2.5q)2
=(2.5p-1.5q-1.5p+2.5q)(2.5p-1.5q+1.5p-2.5q)
=(p+q)(4p-4q)
=4(p+q)(p-q) =4(p2-q2)