80 points)show all your work use the substitution method to solve the system of equations. x + y = 20 30x + 25y = 550

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

Compare the cost of the bike trips from the two companies shown.for both the cost in a linear function of the number of days which statements is true

Which value would be a solution for x in the inequality 47-4x< 7