X would have to equal 10. This would be the answer because the numbers have to be proportional. To do that all you have to do is do 12/8. Then you get 1.5. Then you do the same for 15. Do 15/1.5 and get 10.
★ Arithmetic Progression [ Explicit and Recursive notation ] ★
Arithmetic Sequence - 19 , 9 , -1 ...
Recursive Notation -
First term = 19
Common difference = -10
In subscript notation - [ a₁ = 19 , aₙ = aₙ-₁ -10 ]
In functional notation - f(n) = f (n -1) -10
Explicit Notation - f ( n ) = f ( 1 ) + d ( n - 1 )
= 19 - 10 ( n -1 )
= 29 - 10n
It's functional and subscript notations resides the same
I think the answer is the 2nd to last one, where x would be triggerfish and y would be the parrot fish.
You add because
2842-(-282)
=2842+282
thus the answer will be 3124
