Answer:

Step-by-step explanation:
Let total x black and y brown shoes are sold in a week
So total number of shoes sold in a week is = x+y
It is given that
of all shoes sold are black
So 

So the number of brown shoes sold in a week in terms of black shoes are x/2
X=3 im pretty sure i dont rly have a explanation
Answer:
I don't see choices but -8<0
4(x-2)-3=9
<span>Reorder the terms:
4(-2 + x) + -3 = 9
</span><span>(-2 * 4 + x * 4) + -3 = 9
</span><span>(-8 + 4x) + -3 = 9
</span><span>Reorder the terms:
-8 + -3 + 4x = 9
</span><span>Combine like terms:
-8 + -3 = -11
</span>-11 + 4x = 9
<span>Solving:
-11 + 4x = 9
</span>Add '11' to each side of the equation.
-11 + 11 + 4x = 9 + 11
Combine like terms: -11 + 11 = 0
0 + 4x = 9 + 11
4x = 9 + 11
<span>Combine like terms:
9 + 11 = 20
4x = 20
</span><span>Divide each side by 4.
x = 5</span>
Mean of a data = Sum of all observations ÷ Total number of observations
Mean of this data will be :
Sum of all observarions = 17 + 13 + 18 + 20 + 17 + 15 + 12 = 112
Total number of observations = 7
Mean = 112 ÷ 7
Mean = 16
Therefore the mean of this data set <em>=</em><em> </em><em>1</em><em>6</em><em> </em>