có sai đề k vậy bạn ?

\(\left|5x+6\right|=9\)

\(Th1:\left|5x+6\right|=\left|-9\right|\)

=>\(5x+6=-9\)

=>\(5x=-9-6\)

=>\(5x=-15\)

=>\(x=-15:5\)

=>x=-3

\(Th2:\left|5x+6\right|=\left|9\right|\)

=>\(5x+6=9\)

=>\(5x=9-6\)

=>\(5x=3\)

=>\(x=5:3\)

=>\(x=\dfrac{5}{3}\)

a)\(64^2+36^2+2.64.32\)

=\(^{64^2+2.64.32+32^2}\)

=\(\left(64+32\right)^2\)

=\(96^2\)

=9216

b)\(64^2+36^2-2.64.36\)

=\(64^2-2.64.36+36^2\)

=\(\left(64-36\right)^2\)

=\(28^2\)

=784