1) Given m represent the total number of miles Hannah walked.
Let us assume Hannah walked x miles each day.
So total number of miles Hannah walked in 5 days is m=5x.
2)Given Jimmy brought 2 books per day and Peter brought 4 books per day.
If d is the number of days the book drive, total number of books they brought
=total number books brought by Jimmy+ total number of books brought by Peter
= 2d+4d = 6d
3) Given that c represent cost of the clothes.
Then 30% discount = 0.3c
Hence cost of the clothes = c-0.3c = 0.7c
4) Given c represent the cost of their meal before tipping.
And tip is 15% of the cost.
Hence tip = 0.15c
Hence total bill = c+0.15c=1.15c
5) Given that Tommy had 40$ in his pocket.
And pair of pants cost 37$ with 10% sales tax.
Hence cost of pants including sales tax = 37+37*0.1 = 40.1$ >40$
Hence Tommy cannot afford the pants with 40$ in his pocket.
For following problems, we should group the like terms together and then simplify.
6) (x+8)+(3x-12) = (x+3x)+8-12 = 4x-4
7) 5x+7-(3x-4) = 5x+7-3x+4 = (5x-3x)+7+4 = 2x+11
8) (x-2)-(-4x+1)=x-2+4x-1 = (x+4x)-2-1 = 5x-3