Can yall please help me out with these questions

Aresearch company wants to test the claim that a new multivitamin to improve short term memory. state the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.

What is the equation of the following graph in vertex form? parabolic function going down from the left through the point zero comma twelve and through the point two comma zero and turning at the point four comma negative four and going up through the point six comma zero and continuing towards infinity courtesy of texas instruments a: y = (x − 4)2 − 4 b: y = (x + 4)2 − 4 c: y = (x + 2)2 + 6 d: y = (x + 2)2 + 12

Which value of c would make he following expression completely factored? 8x+cy