Answer:
w = 3 or 6
Step-by-step explanation:
[tex]w {}^{2} - 9w + 18 = 0 \\ w {}^{2} - 6w - 3w + 18 = 0 \\w(w - 6) - 3(w - 6) = 0 \\ w - 3 = 0 \\ w - 6 = 0 \\ w = 3 \: or \: 6[/tex]