Step-by-step explanation:
its a triangle so find XZ then use cosine rule to find angle X
Answer:$9504.80
Every year, we have an increase of 9% interest. After two years, we will have 8000 * 1.09 ^2 = $9504.80
(x - 9)(x + 9) would give you x^2 - 81 when you get a plus and minus like that after you factor the middle term is canceled out so the answer would be (x - 9)^2
