13) Solve algebraically through elimination:
3x + y = -21
-X-y-5

Which is an equation for the nth terms of the sequence 12,15,18,21

Simplify 4 square root of 2 end root plus 7 square root of 2 end root minus 3 square root of 2 . (1 point) 2 square root of 8 8 square root of 2 8 square root of 6 6 square root of 8

In two or more complete sentences describe how to determine the appropriate model for the set of data, (1,1), (3,2), (6,3), (11,4).