Question

ME AJUDE , POR FAVOR !

Answer 1

$a)~~(3y-4).(3y+1)=14-9y\\\\ 3y ^{2}+3y-12y-4=14-9y\\ 3y^{2}-9y-4=14-9y\\ 3y^{2}-9y+9y=14+4\\ 3y ^{2}=18\\\\ y ^{2}= \frac{18}{9}\\\\ y ^{2}=2\\\\ y= \sqrt{2}\\\\ y=\pm \sqrt{2}\\\\\\\\ \boxed{S=\{- \sqrt{2}, \sqrt{2}\}}$
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$b)~~(m+5).(m-4)=m+16\\\\ m^{2}-4m+5m-20=m+16\\\\ m ^{2}+m-m=16+20\\\\ m ^{2}=36\\\\ m= \sqrt{36}\\\\ m=\pm6\\\\\\\\ \boxed{S=\{-6,6\}}$


Espero ter ajudado e tenha ótimos estudos ;D