Question 637292
{{{(2-sqrt(7))^2}}}
IMPORTANT: Exponents so <u>not</u> distribute! So simplifying this expression is <u>not</u> done by squaring the 2 and squaring the square root!!<br>
To simplify this expression we can either use FOIL on {{{(2-sqrt(7))(2-sqrt(7))}}} or use the {{{(a-b)^2 = a^2-2ab+b^2}}} pattern.<br>
I prefer using the pattern. With an "a" of "2" and a "b" of "{{{sqrt(7)}}}", the pattern tells us that
{{{(2-sqrt(7))^2}}}
would be
{{{(2)^2-2(2)(sqrt(7))+(sqrt(7))^2}}}
which simplifies as follows:
{{{4 - 4sqrt(7) + 7}}}
{{{11 - 4sqrt(7)}}}