What is equivalent to 3x+3y=8 and 2x-y=5

Roger and natalie travel in similar cars. roger's car drives the two miles to school in 7.5 minutes. natalie drives the same distance in the opposite direction but in only 6.5 minutes. what is true of their velocities?

Which value is not a solution of 8x^3 – 1 = 0

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days