Question 547996


{{{(k+10)^2}}} Start with the given expression.



{{{(k+10)(k+10)}}} Expand. Remember something like {{{x^2=x*x}}}.



Now let's FOIL the expression.



Remember, when you FOIL an expression, you follow this procedure:



{{{(highlight(k)+10)(highlight(k)+10)}}} Multiply the <font color="red">F</font>irst terms:{{{(k)*(k)=k^2}}}.



{{{(highlight(k)+10)(k+highlight(10))}}} Multiply the <font color="red">O</font>uter terms:{{{(k)*(10)=10*k}}}.



{{{(k+highlight(10))(highlight(k)+10)}}} Multiply the <font color="red">I</font>nner terms:{{{(10)*(k)=10*k}}}.



{{{(k+highlight(10))(k+highlight(10))}}} Multiply the <font color="red">L</font>ast terms:{{{(10)*(10)=100}}}.



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So we have the terms: {{{k^2}}}, {{{10*k}}}, {{{10*k}}}, {{{100}}} 



{{{k^2+10*k+10*k+100}}} Now add every term listed above to make a single expression.



{{{k^2+20k+100}}} Now combine like terms.



So {{{(k+10)^2}}} FOILs to {{{k^2+20k+100}}}.



In other words, {{{(k+10)^2=k^2+20k+100}}}.