Answer: 12+n
Step-by-step explanation:
Los gramos son más de miligramos
9-2(-3)+6= 9+6+6 Your answer should be 21 if I read your question correctly
Answer: 
Step-by-step explanation:
Given
Vertex of the parabola 
Focus of the parabola 
As the x coordinate of vertex and focus is same and focus lie below the vertex, therefore the parabola is the type of

distance between Vertex and focus is 1 unit

Parabola becomes

Simple. Just add/subtract each term. 4n-2n=2n. 8m+7m=15m.
This is very basic stuff.