Volume of a cylinder: v=πr to the power of 2 h;solve for h

V = π * r2 * h, and r + h = 12

You have 2 independent variables, so use both equations to develop a formula for V. It seems best to use substitution for h, to keep the equation relatively simpleSo:

r + h = 12

rearrange to get: h = 12 - r

Substitute in the 1st equation to get:

V = π * r2 * (12 - r)

Expand:

V = 12πr2 - πr3

To find a maximum (or minimum), the typical method is to find the 1st derivative and set it equal to zero.

V' = 24πr - 3πr2

Set equal to 0 and solve for r:

24πr - 3πr2 = 0

8r - r2 = 0

r = 0, 8 (Interpretation: 0 gives you the minimum volume, and 8 gives you the maximum)

Step-by-step explanation:

hope this will help you

i think u have 12 apples sorry again i don't really know if it correct i'm just tryna hrlp people out.

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -