Question

(2.5х-0.3y)(2.5х+0.3y)

Answer 1

( 2,5х - 0,3y )( 2,5x + 0,3y ) = 6,25x^2 - 0,09y^2

Answer 2

$(a-b)(a+b) = a ^{2} -b ^{2} \ \ \ \ (2,5x-0,3y)(2,5x+0,3y)= (2,5x) ^{2} -(0,3y) ^{2} =6,25 x^{2} -0,09y ^{2}$