Which of the following sets of values is a solution to the following system of linear equations?

4x + y = 24

x - y = -4

a.) x = 4,y =8

b.) x = 2,y = 6

c.) x = 1,y = 1

d.) x = 5,y = 4

also explain why.

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

Lucy is a dress maker. she sews \dfrac47 7 4 of a dress in \dfrac34 4 3 hour. lucy sews at a constant rate. at this rate, how many dresses does lucy sew in one hour? include fractions of dresses if applicable

Campus rentals rents 2 and 3 bedrooms apartments for $700 ans $900 a month respectively. last month they had six vacant apartments and reported $4600 in lost rent. how many of each type of apartment were vacant?