ALHersey, post question 4 again. Its data is incomplete. Now the methods for the four problems are
For 1: Write 0.4/0.08 as (4/10)/(8/100) and then try to solve it.
For 2: Percentage is calculated by the formula (x/y)x100%, where x is the amount(here, 15) and y is the total value(here, 30)
For 3:You can write 2 1/2 as 5/2, 3 3/4 as 15/4 and 4 3/5 as 23/5. Now follow the rules of addition.
Or else, you can simply add the whole number part (4+3-2) and the fraction part(3/5+3/4-1/2) separately and then add them to get the result.
For 4: This one is based on the assumption that you know the points. Simply, put the coordinates as x and y. (Example: To check if (3,5) satisfies the given condition, put 3 as x and 5 as y. Both sides of the '=' sign should be equal for the point to satisfy the condition.)