Question 106191
{{{(a+5)^2=a^2+10a+25}}} Expand the right hand side. 
{{{(a+5)^2=(a^2+10a)+25}}}
{{{(a+5)^2=10*(a^2/10+a)+25}}}Distributive property.
{{{(a+5)^2=10*10*(a^2/10^2+a/10)+25}}}Distributive property.
{{{(a+5)^2=10*10*(a/10)*(a/10+1)+25}}}Distributive property.
Example:
{{{a=60}}}
{{{a/10=6}}}
{{{a/10+1=7}}}
{{{(a+5)^2=10*10*(a/10)*(a/10+1)+25}}}
{{{(60+5)^2=10*10*(60/10)*(60/10+1)+25}}}
{{{65^2=100*6*7+25}}}
{{{4225=4225}}}