Answer:
140
Step-by-step explanation:
80 Divied by 4 is 20
SO Each Pair Is 20
7 x 20 = 140
It would be $20 a pair.
21, 24, 27, 30, 33, 36, 39.
x = -6
-18+4y=0 => 4y=18 =>y=18/4=9/2
Y=5
3x+20=0 => x=3x= -20=> x= -20/3
