Answer:
81x² - 81
Step-by-step explanation:
Step 1: Write expression
(9x - 9)(9x + 9)
Step 2: Expand by FOIL
81x² + 81x - 81x - 81
Step 3: Combine like terms
81x² - 81
Answer:the model predicts that you will win 6 prizes when you buy 10 tickets.
Step-by-step explanation:
Let p be: John goes to the beach
Let q be: He will go surfing.
Then in symbolic form, the argument becomes:

p ⇒ q
p
---------------------
∴ q
An argument is valid if the conjuction of the premises implies the conclusion.
p | q | p ⇒ q | (p ⇒ q) ∧ p | [(p ⇒ q) ∧ p] ⇒ q
---------------------------------------------------------------------\
F | F | T | F | T
F | T | T | F | T
T | F | F | F | T
T | T | T | T | T
The table above shows that the argument is a tautology.
Hence, the argument is valid
The answer is
-26 & -25
it's sum = -26+(-25
= -26-25
= -51