Answer:
x = - 6
Step-by-step explanation:
Given that y varies directly as x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = - 9 when x = 3, thus
k = =
= - 3
y = - 3x ← equation of variation
When y = 18, then
18 = - 3x ( divide both sides by - 3 )
x = - 6
Answer: -9n+20
This is the same as 20-9n
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Explanation:
The jump from 11 to 2 is "minus 9"
The jump from 2 to -7 is also "minus 9".
Assuming this pattern continues on, we have an arithmetic sequence with
The nth term can be found like so
Let's check the answer by trying n = 3
This shows the third term is -7, which matches what the original sequence shows. The answer is partially confirmed. I'll let you check the other values of n. You should get 11 when trying n = 1, and you should get 2 when trying n = 2.