What is the value of z so that-9 and 9 are both solutions of x^2+z=103?

a) -22
b) 3
c) 22
d 184

Anyone know? will mark brainliest if correct

Arestaurant charges $100 to rent its banquet room for an event. it also charges $15 to serve dinner to each guest. write an equation for the total cost of the banquet room in terms of the number of guests. deine your variables. what is the total cost of the banquet room for 20 guests?

Two groups of students were asked how many hours they spent reading each day. the table below shows the numbers for each group: group a 1 2 1 1 3 3 2 2 3 group b 3 2 3 2 2 2 1 1 2 based on the table, which of the following is true? the interquartile range for group a students is 0.5 less than the interquartile range for group b students. the interquartile range for group a students is equal to the interquartile range for group b students. the interquartile range for group a employees is 0.5 more than to the interquartile range for group b students. the interquartile range for group a employees is 1 more than the interquartile range for group b students.