Question

(2.5x+3.2y-3c)-6.2x-3.7y+8c)

Answer 1

Supongo que es: (2.5x+3.2y-3c)(-6.2x-3.7y+8c)
Por lo tanto 

(2.5x)(-6.2x-3.7y+8c)+(3.2y)(-6.2x-3.7y+8c)-(3c)(-6.2x-3.7y+8c)
=(-15.5x²-9.25xy+20xc)+(-19.48xy-11.84y²+25.6yc)-(-18.6xc-11.1cy+24c²)
=-15.5x²-9.25xy+20xc-19.48xy-11.84y²+25.6yc+18.6xc+11.1cy-24c²
=-15.5x²-28.73xy+36.7xc-11.84y²-24c²