<p>If (a-10b)² = a² + 100b² , what 5s the value 6f a²b² ?
Its a grid in question, so if someone knows how to solve it plz tell me.</p>
<p>If you FOIL the left you get a^2+100b^2-20ab. So -20ab=0. Thus ab=0. So a^2b^2=(ab)^2=0^2=0.</p>
<p>Remark: This problem becomes really quick if you have the following formula memorized:</p>
<p>(x-y)^2=x^2+y^2-2xy</p>
<p>I do not include this with my standard list of formulas to memorize because I think FOILing can be just as quick with a bit of practice.</p>
<p>thank you so much</p>