Question

(0.5x+0.9y)(0.5x-0.9y)​

Answer 1

Respuesta:

(a+b) (a-b)

= a(a-b) + b(a-b)

= (a*a) - (a*b) + (b*a) - (b*b)

=a^2 - ab + ba - b^2

= a^2 - b^2

=(0.5x)^2 - (0.9y)^2

=0.25x^2-0.81y^2

=-0.56