To find the midpoint, Add the two X coordinates together then divde by two and then to the same with the Y coordinates:
X = -4 + 2 = -2 / 2 = -1
Y = 6+7 = 13/2
Midpoint = (-1,13/2)
X = number of cds on the rack
x + 7 = 30
x = 30 - 7
x = 23 <== so there are currently 23 cds on the rack
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Given:

Step-by-step explanation:

Identity used:

Answer:
this will probably help
Step-by-step explanation: