Let n be a number of balls: n = 14
In one pan you have 8 balls: 8n
In the other pan you have the rest of balls (14 - 8 = 6) along with a <span>weight of 20 grams = 6n + 20
So the pans are balanced:
8n = 6n + 20
Now, just solve the equation:
8n - 6n = 20
2n = 20
n = 20/2
n = 10
So, you know that a ball weights 10 grams.</span>
Answer:
x = 10 cm, y = 5 cm gives a minimum area of 300 cm^2.
Step-by-step explanation:
V= x^2y = 500
Surface area A = x^2 + 4xy.
From the first equation y = 500/x^2
So substituting for y in the equation for the surface area:
A = x^2 + 4x * 500/x^2
A = x^2 + 2000/x
Finding the derivative:
dA/dx = 2x - 2000x^-2
dA/dx = 2x - 2000/x^2
This = 0 for a minimum/maximum value of A, so
2x - 2000/x^2 = 0
2x^3 - 2000 = 0
x^3 = 2000/ 2 = 1000
x = 10
Second derivative is 2 + 4000/x^3
when x = 10 this is positive so x = 10 gives a minimum value of A.
So y = 500/x^2
= 500/100
= 5.
Area of a triangle= bh/2b=4in h=8in8x4/2=16in
there are 4 triangles
4x16=64
area of a rectangle=bh
4x4=16
64+16=80in^2
Answer
w=18
Step-by-step explanation:
