SOLVE each system of equations below by substitution 1. y = -3x – 16 and 5x – 2y = -23
2. 6y – 3x = -9 and x = -2y + 5
3. y + 4 = 3x and 2y – 6x = -8

Astandard american eskimo dog has a mean weight of 30 pounds with a standard deviation of 2 pounds. assuming the weights of standard eskimo dogs are normally distributed, what range of weights would 99.7% of the dogs have? approximately 26–34 pounds approximately 24–36 pounds approximately 28–32 pounds approximately 29–31 pounds

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

Math it's appreciated. (picture provided)