Answer:
x = 2, y = -3
Step-by-step explanation:
Add them together and get
9x + 8y - 9x - 9y = -6 + 9
-y = 3
so y = -3.
Sub it into the first equation and get
9x + 8(-3) = -6
9x - 24 = -6
9x = -6 + 24 = 18
x = 18/9 = 2
Answer:
Your answer is correct. The series is a geometric series with common ratio -1/4 and first term 40. So each term is:
an = 40 (-1/4)^(n−1)
So the sum of the first 10 terms is:
∑(n=1 to 10) [ 40 (-1/4)^(n−1) ]