Question 147738


{{{(9x-8)^2}}} Start with the given expression.



{{{(9x-8)(9x-8)}}} 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(9x)-8)(highlight(9x)-8)}}} Multiply the <font color="red">F</font>irst terms:{{{(9*x)*(9*x)=81*x^2}}}.



{{{(highlight(9x)-8)(9x+highlight(-8))}}} Multiply the <font color="red">O</font>uter terms:{{{(9*x)*(-8)=-72*x}}}.



{{{(9x+highlight(-8))(highlight(9x)-8)}}} Multiply the <font color="red">I</font>nner terms:{{{(-8)*(9*x)=-72*x}}}.



{{{(9x+highlight(-8))(9x+highlight(-8))}}} Multiply the <font color="red">L</font>ast terms:{{{(-8)*(-8)=64}}}.



{{{81*x^2-72*x-72*x+64}}} Now collect every term to make a single expression.



{{{81*x^2-144*x+64}}} Now combine like terms.



So {{{(9x-8)^2}}} FOILS to {{{81*x^2-144*x+64}}}.



In other words, {{{(9x-8)^2=81*x^2-144*x+64}}}.