Step-by-step explanation:

Answer:
C. SA = 148.8 ft
Step-by-step explanation:
3.1×8×6= 148.8
2x(-5x-3)
2x(-5x)= -10x and 2x(-3)= -6x
= -10x sq - 6x
-10x is sq bc you are multiplying the same variable twice
Train A weighs 181 tons and train B weighs 70 tons.