Answer:
a square backyard with width (x - 9)
Step-by-step explanation:
x²−18x + 81 = x² - (2 x 9) x + 9² = (x - 9)²
width = area / length = (x - 9)² / (x - 9) = x - 9
Length = width
This is a square backyard
There would approximately be 36 ordered triples
To calculate expected value,
We can add up the probability of all possible events.
The 2 possible events are either winning $50 or losing the prize, which is $ - 50
Expected value =
50 x 40 % + (-50) x 60%
= $-10
So the answer is $-10
The answer is C.......Sports Stamps = 4 , Holiday Stamps = 2 , Presidents Stamps = 8. He said 4 times as many presidents than holiday. So the number of presidents stamps is the product of the holiday stamps times 4. 4 times 2 is 8. Add them all together
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.
