<span>3mx^2y/2a^2b^2 * 3abc/8p^2g^2 : 9a^2b^2c^3/28xpg =
= 9</span><span>mx^2yc/16abp^2g^2 * 28xpg/9a^2b^2c^3 =
= 14mx^3y / 8a^3b^3c^2pg
</span>
(6-y)(6+y)/(y-8)(y/(y-6)-2y/(y-6)^2)+12y/(y-6)=
=(6-y)(6+y)/(y+8)*(y^2-8y)/(y-6)^2+(12-y)/(y-6)=
=-y(6+y)/(y-6)+12y/(y-6)=(-6y-y^2+12y)/(y-6)=(6y-y^2)/(y-6)=y(6-y)/(y-6)=-y
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