It helps to imagine the variable a sort of as a unit. Like with 5 minus 12 lemons, it has no bearings on the addition/subtraction here.
Factor out a and subtract.
Answer:
D
Step-by-step explanation:
If it was 6 degrees cooler on Monday than it was on Sunday, but also having Tuesday be 4 degrees warmer than Monday, Wednesday would have to be 2 degrees cooler than Tuesday because it is a number that would comply with the limits
200+40=240
each train cost 10
take 240/10=24trains