What is the first step when rewriting y=-4x^2+2x-7 in the form y=a(x-h)^2 +k

I’m stuck on this i don’t understand.

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.

What is the measure of angle 1? a.28 b.152 c.168 d.64