Answer:
the cost of each cookie is 
the cost of each muffin is 
Step-by-step explanation:
Let
x-----> the cost of each cookie
y----> the cost of each muffin
we know that
-----> equation A
-----> equation B
Using a graphing tool
The solution of the system of equations is the intersection point both graphs
The intersection point is 
see the attached figure
therefore
the cost of each cookie is 
the cost of each muffin is 
Answer:
0.75m
Step-by-step explanation:
The volume of a prism is:
the area of the cross section × length
In this case the cross section is the circle so the formula is
v = πr²h
volume = 21m³
height or length = 12m
Sub in the values:
21 = πr² × 12
1.75 = πr² (I divided both sides by 12)
0.5570423008 = r² (I divided both sides by π)
r = 0.74635... (I square rooted both sides)
r ≈ 0.75m (to 2 d.p)