Help please thanks I’ll give 13 points

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

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

Atriangle in the coordinates of (2,3), (-4,5) and (-2,4) it is translated 3 units down. what are it’s new coordinates