The answer is 6.5t2+0.5t−5.5 , it’s simplified
The answer you put is correct
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
2:B
Attached:C
Unfortunately don't know the other two