QA НА / Terrizzi read Best Buy's ad this past weekend. They are selling a 42 inch plasma TV for $349.99. If 42 inches is the dia
1 answer:
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Answer: The difference between the larger and smaller number is 21.
Step-by-step explanation:
This can be translated to:
"the multiplication between 3 numbers is 1000 and the addition is 39.
If the first number is at the second like the second at the third, find the difference between the smaller and the larger number"
If A is the first number, B the second and C the third we have that:
A*B*C = 1000
A + C + B = 39
A/B = B/C
From the third equation we have that:
A*C = B*B
we can replace it in the first equation and get:
B*(A*C) = 1000
B*B*B = B^3 = 1000
So now we have the value of B.
Now we have the two equations:
A + 10 + C = 39
A*C = B*B = 10*10 = 100
We can isolate A in the first equation and get:
A = 39 - 10 - C = 29 - C
now we can replace it in the second equation:
(29 - C)*C = 100
29C - C^2 - 100 = 0
We need to find the roots of that equation, we can use the Bhaskara's function:
Where we have two possible values for C
C = (-29 - 21)/(-2) = 25
C = (-29 + 21)/(-2) = 4
Let's chose C = 4, because C is the smaller value. (A will take the other value)
Then we have:
A + B + C = 39
A + 10 + 4 = 39
A = 39 - 14 = 25
Then the difference between the larger and smaller number is:
A - C = 25 - 4 = 21
Answer:
1 hour and 15 minutes
or
1.25 hr.
Step-by-step explanation:
40 miles ⇒ 1 hr.
50 miles ⇒ total hours
= 1.25 hours