6 sma 7 dong, tolong pake caranya ya

6.
[tex] {x}^{2} - 18x + 72 = 0 \\ (x - 12)(x - 6) = 0 \\ x = 12 \\ x = 6[/tex]
7.p+q=1/3, pq= -5
[tex] \frac{ {p}^{2} + {q}^{2} }{pq} = \frac{ {(p + q)}^{2} - 2pq}{pq} = \\ \frac{ \frac{1}{9} + 10}{ - 5} = - 2 \frac{1}{45} [/tex]