Bu soruyu çözümü ile birlikte cevaplayabilir misiniz, acil?​

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)