color(blue)( - 5) ( c+d) -4d + 5c - d
= color(blue)( (- 5)) * ( c) + color(blue)( (-5) ) * (d) -4d + 5c - d
= color(green)(- 5 c) -5 d -4d + color(green)(5c) - d
= cancelcolor(green)(- 5 c) -5 d -4d + cancel color(green)(5c) - d
= -5 d -4d - d
= color(green)(- 10d)