Fo part a: You would have the answer of 6x +12 since both side is x (2x together) then the longer side would be 2x+6 but then u would have to multiply by 2 since there are 2 sides (4x+12) Then if u combined it you would get 6x+12 for part a
Answer:
The pic is below :)
Step-by-step explanation:
Speed =distance/ time taken =100/0.4 =250 miles/ hour