Will a teaspoon be a good way to measure the capacity of a milk carton

Amber had 1/6 of a pie left after the bake sale. rihanna had 3/8 of a pie left. what fraction of a pie did they have altogether?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?