
The given equation is :
1. The relationship such that dependent variable (y) is isolated is :
2. The table accompanying this equation :
3. graph of the given equation is in attachment ~
For #1 it's going to be proper because it's pretty specific, and for number two it's going to be all common because it's not citing anything specific.
DE + EF = 4x+2
DE = x+7
EF = 7
Substitute these in
x + 7 + 7 = 4x + 2
x + 14 = 4x + 2
subtract x from both sides
14 = 3x + 2
subtract 2 from both sides
3x = 12
divide both sides by 3
x = 4
substitute this in to find the length of DE
DE = x + 7
(4) + 7 = 11
the answer is 11
Answer: the answer is C . 19.5 units - APEX :D