Answer:
Below in bold.
Step-by-step explanation:
-8xy-6xz + 10xy + 9xz - 4yx (Note 4yx = 4xy)
Bringing like terms together we have:
-8xy + 10xy - 4xy - 6xz + 9xz
= -2xy + 3xz.
m² - 4m - 1 + m² - 8m + 5-6m² +3m - 1
= m² + m² - 6m² - 4m - 8m + 3m - 1 + 5 - 1
= -4m² - 9m + 3.
