This is due tomorrow and i don't understand it. !

Find the values of y: 3y^3(y^2+ 2/3y)=0

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

Your family took a road trip on saturday you were in the car for 4.5 hours and average 70 mph. how many miles did you travel?