Me this is really urgent for me on question 14) ok

How to write 3 tenths and 5 tenths as a decimal

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).