Answer:
See Below
Explanation:
If DF = 42, What is DE?
D__________E_______F
(7x + 1) + ( 4x-3) = 42
7x+1+ 4x -3 = 42 Solve for x
11x -2 = 42
+2 +2
11x = 44
11x / 11 = 44/ 11
x = 4
Now plug x in for the equation of DE
7x+1
7(4) + 1
28 + 1 = 29
DE = 19