Question 764376
<pre>
9x to the fourth power minus 25x to the second power plus 16 is equal to zero

While the other person's solutions/roots are correct, I don't see any sense in the method that he/she used to get them!!

                 {{{9x^4 - 25x^2 + 16 = 0}}}
            {{{9x^4 - 9x^2 - 16x^2 + 16 = 0}}} ----- Substituting {{{matrix(1,3, - 9x^2 - 16x^2, for, - 25x^2)}}}
        {{{9x^2(x^2 - 1) - 16(x^2 - 1) = 0}}} ----- Factoring out GCF for binomials {{{9x^4 - 9x^2}}} and {{{16x^2 + 16}}}
             {{{(9x^2 - 16)(x^2 - 1) = 0}}} 
(3x - 4)(3x + 4)(x - 1)(x + 1) = 0 ----- Factorizing each binomial
(3x - 4) = 0 ; 3x + 4 = 0 ; x - 1 = 0 ; x + 1 = 0 ----- Setting each factor equal to 0
              {{{highlight(matrix(1,7, x = 4/3, ",", x = - 4/3, ",", x = 1, ",", x = - 1))}}}</pre>