4.
1 answer:
You might be interested in
Answer:
Height: 3/2 inches
Length: 12 inches
Width: 4 inches
Step-by-step explanation:
Let x is the side length of the square
The height of the box by cutting squares off :x
- The new length of the cardboard = 15 -2x (because we cut from 4 corners)
- The new width of the cardboard = 7 -2x (because we cut from 4 corners)
The new volume of it is:
V = (15 -2x) (7 -2x) x
<=> V =
To maximum volume, we use the first derivative of the volume
<=>
<=>
<=> 2x -3 = 0 or 6x -35 = 0
<=> x = 3/2 or x = 35/6
To determine which value of x gives a maximum, we evaluate
= 24x -88
- If x = 3/2, we have:
= 24(3/2) -88 = -52
- If x = 35/6, we have:
= 24(35/6) -88 = 52
We choose x = 3/2 to have the maximum volume because the value of x that gives a negative value is maximum.
So the dimensions (in inches) of the box is:
Height: 3/2 inches
Length: 15-2(3/2) = 12 inches
Width: 7 - 2(3/2) = 4 inches
Answer: Brian gets $39.2 more over Colin.
Step-by-step explanation:
Given: Total tip amount = £78.40
The ratio of the share of tips for Pawl, Colin and Bria is 2:1 :5.
Let tip amount for Pawl = 2x, tip amount for Colin = x , tip amount for Bria = 5x
Then, 2x+x+5x= 78.40
Tip for Colin = $ 9.8 , Tip for Bria = 5($9.8)= $49
Difference = $(49-9.8) = $ 39.2
Hence, Brian gets $39.2 more over Colin.
