Answer:
Step-by-step explanation:
The diameter is just the radius times two, so divide the diameter by two and you will have the radius of the circle.
Answer: 
Step-by-step explanation:
divided by 
is the same thing as multiplying by 
.
The equation we get is:
With this equation, we can factor each equation:
We can cancel out like terms since they would be dividing each other:
Answer:
15
15
10
Step-by-step explanation:
3/8 x £40 = £15 for Sarah
3/8 x £40 = £15 for Fiona
2/8 x£40 = £10 for david
It's D, it's the only one where it has a -6 at the end other than A, but if you look at the A when distributed there isn't a 23x<span />
Answer:
h /r = 2.55
Step-by-step explanation:
Area of a can:
Total area of the can = area of (top + bottom) + lateral area
lateral area 2πrh without waste
area of base (considering that you use 2r square) is 4r²
area of bottom ( for same reason ) 4r²
Then Total area = 8r² + 2πrh
Now can volume is 1000 = πr²h h = 1000/πr²
And A(r) = 8r² + 2πr(1000)/πr²
A(r) = 8r² + 2000/r
Taking derivatives both sides
A´(r) = 16 r - 2000/r²
If A´(r) = 0 16 r - 2000/r² = 0
(16r³ - 2000)/ r² = 0 16r³ - 2000 = 0
r³ = 125
r = 5 cm and h = ( 1000)/ πr² h = 1000/ 3.14* 25
h = 12,74 cm
ratio h /r = 12.74/5 h /r = 2.55
