Answer: False, there are actually 900 different three-digit numbers
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Explanation:
The three digit numbers span from 100 to 999, including both endpoints.
This means we have 999-100+1 = 900 different three-digit numbers.
You subtract the endpoints (large-small) and add 1 to include the lower endpoint.
Here's a smaller example of why this works: say you had the set {1,2,3,4} and we wanted to count the number of items in this set. Clearly there are 4 items. Note how subtracting the endpoints 4-1 gets us 3 instead, so we add on 1 to include that left endpoint.
So we have the equations:
y - 4x = 2 --- equation 1
5y - 2x = 1 --- equation 2
(equation 2) * 2
10y - 4x = 2 --- equation 3
(equation 2) - (equation 3)
-9y = 0 so y= 0 and thus x = -1/2
Hope that helps!
Answer:
AB = 5 units
BC = 5
units
AC =
or about 6.4 units
Step-by-step explanation:
distance formula: square root of the sum of the difference of the y-values and the difference of the x-values
ex, dAB = √(4-0)² + (3-0)²
= √16 + 9
= √25
= 5
9514 1404 393
Answer:
375 hamburgers
Step-by-step explanation:
Let h represent the number of hamburgers. Then h+63 is the number of cheeseburgers, and the combined total is ...
h +(h +63) = 813
2h = 813 -63 = 750
h = 750/2 = 375
375 hamburgers were sold on Saturday.
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<em>Additional comment</em>
In a "sum and difference" problem like this, the smaller number is half the difference between the sum and the difference. h = (813 -63)/2 = 375. This generic solution applies to all "sum and difference" problems.