Equations:
m = k + 5
k = s + 2
m + k + s = 30
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Substitute for "m" and for "s"::
k+5 + k + k-2 = 30
3k +3 = 30
3k = 27
Kirsty has 9 marbles
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Mina has 9+5 = 14 marbles
Seb has 9-2 = 7 marbles
Answer:
x = 3
y = -2
Step-by-step explanation:
I honestly don't understand the question I think you made a mistake writing it but I think I have an idea about it.
Answer:

Step-by-step explanation:
This shape is called a rectangular prism. The formula for finding the volume of this prism is: 
All you do is plug the values into the formula.
The length is 2m
The width is 1m
the height is 5m
Volume = (2m)(1m)(5m)
Volume = 
Step-by-step explanation:
the answer is:
x=180-90-70=20°