Question 134394
# 1


Take half of the "c" coefficient to get -2. In other words, {{{(1/2)*(-4)=-2}}}



Now square the result to get 4. In other words, {{{(-2)^2=(-2)(-2)=4}}}



So you must add 4 to the expression to get 


{{{c^2-4c+4}}}


So the expression is now a perfect square



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# 2


Take half of the "b" coefficient to get {{{4/6}}} or {{{2/3}}}. In other words, {{{(1/2)*(4/3)=4/6=2/3}}}



Now square the result to get {{{4/9}}}. In other words, {{{(2/3)^2=(2/3)(2/3)=4/9}}}



So you must add {{{4/9}}} to the expression to get 


{{{b^2+(4/3)b+4/9}}}


So the expression is now a perfect square