Definitions
Combine like terms:
2x+5y-2y+15-12
2x+3y+3
Use order of operations:
2(5+x)-4
6+2x
is this a linear equation?
3x+y=12
Yes
Function or relation:
Every input has one output
Function
Find the mid-point of these two points:
(5,10) and (3,8)
(4,9)