Let x be the number of pages of advertisements.
Write a proportion from the table:
of a page of advertisment - 5 pages in a magazine
x pages of advertisment - 98 pages in a magazine,
then
Find x:
Answer: 13 whole pages and 
of 14th page are advertisments, so 14 pages contain advertisments.
1. 7 and -7 are both 7 units away from 0. They are 14 units away from each other. Absolute value helps because rather than 7+(-7) being 0 absolute value makes anything positive so it becomes 7+7=14 to be able to count the units between the two.
2. 5 and -5 are both 5 units away from 0. They are 10 units away from each other. Absolute value helps because rather than 5+(-5) being 0 absolute value makes anything positive so it becomes 5+5=10 to be able to count the units between the two.
3. 2 and -2 are both 2 units away from 0. They are 4 units away from each other. Absolute value helps because rather than 2+(-2) being 0 absolute value makes anything positive so it becomes 2+2=4 to be able to count the units between the two.
Hope that helps
Answer:
7x-3 = 5x+ 15
2x-3 = 15 (you will need to subtract the variables to get 2x)
2x = 18 (next, add the constants to result up to 18)
x = 9 (lastly, divide the constant 18 with the coefficient 2 to get 9)
