What is the length? in algebra due tomorrow

Triangle knm is what is true about the sides of knm

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11

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.