Question 453363
<pre>
(sub subject is Factoring)

solve {{{49a^2-56a+16=0}}} 
please justify your answer thank you

Another WRONG answer by the other person. 

{{{49a^2 - 56a + 16 = 0}}} is in the form: {{{(a - b)^2 = 0}}}, NOT {{{(a + b)^2 = 0}}}, as the other person states.
So, it should be {{{(7a - 4)^2}}}, <font color = red><font size = 4><b>NOT</font></font></b>{{{(7a + 4)^2}}}.
Therefore, we get: {{{49a^2 - 56a + 16 = 0}}}
                         {{{(7a - 4)^2 = 0}}}
                      {{{sqrt((7a - 4)^2) = sqrt(0)}}} ----- Taking square root of both sides
                          7a - 4 = 0
                              7a = 4
DOUBLE Roots/Solutions are located at {{{highlight(a = 4/7)}}}</pre>