Answer:
[tex]\huge\boxed{\sf w = 8}[/tex]
Step-by-step explanation:
[tex]\sf -91 = 6w - 15w - 19\\\\-91 = -9w-19\\\\Adding \ 19 \ to \ both \ sides\\\\-91 + 19 = -9w\\\\-72 = -9w\\\\Dividing \ both \ sides \ by \ -9\\\\-72 / -9 = w\\\\8 = w\\\\w = 8 \\\\\rule[225]{225}{2}[/tex]
Hope this helped!