Answer:
75
Step-by-step explanation:
45*1/3=15
15*5=75
X=60 and y=20
x and y can be many things that answers the question to 120
15. -(-7y + 12) = 7y - 12
16. 1/a = 16/18
cross multiply
16a = 18
a = 18/16 = 9/8
17. 8x - 12 = 4x + 24
8x - 4x = 24 + 12
4x = 36
x = 36/4
x = 9
18. -6b > 42 4b > -4
b < 42/-6 b > -4/4
b < - 7 b > -1
so b < -7 and b > -1
19. 6 more then the product of 8 and n
6 + 8n
20. 45 = 3b + 69
45 - 69 = 3b
-24 = 3b
-24/3 = b
-8 = b
The mean is when you add up all the numbers and divide by the amount of numbers there are.
143+312+41+28+308+619+321+352+465=2589
2589/9=287.666666667
round to the whole number you get
288