C
because in X, the difference from 4 to 6 is 2, the difference from 6 to 10 is 4, the difference from 10 to 12 is 2
so n = 3
in Y, 1 to 9 is 8, 21 to 25 is 4.
9 + 6 is 15
b
step-by-step explanation:
given
- 2 (3x + 12y - 5 - 17x - 16y + 4 )
simplify the parenthesis by collecting like terms
= - 2 (- 14x - 4y - 1) ← distribute the parenthesis by - 2
= 28x + 8y + 2 → b