




(c-d)(c-d)=(d-c)(d-c)
c.c-c.d-d.c+d.d=c2-cd–dc+d2=c2-2cd+d2
d.d-d.c-c.d+c.c=d2-2dc+c2=

(y+d)(y+d)=y2+yd+dy+d2=y2+2yd+d2

25x-12-23x=2x-12

16+2y+8y+y2=16+10y+y2





(c-d)(c-d)=(d-c)(d-c)
c.c-c.d-d.c+d.d=c2-cd–dc+d2=c2-2cd+d2
d.d-d.c-c.d+c.c=d2-2dc+c2=
(y+d)(y+d)=y2+yd+dy+d2=y2+2yd+d2
25x-12-23x=2x-12
16+2y+8y+y2=16+10y+y2