(3)4+5 what is this answer i need to find it

Hi my sisters and brothers can tell me the answer because i don’t understand the question

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is