Question 340330
{{{c^2-6c(a-c)+9(a^2-2ac+c^2)=c^2-6ca+6c^2+9a^2-18ac+9c^2}}}
{{{c^2-6c(a-c)+9(a^2-2ac+c^2)=16c^2-24ca+9a^2}}}
{{{c^2-6c(a-c)+9(a^2-2ac+c^2)=(4c-3a)^2}}}
I get the same answer. 
Something's up with your book.