1 + 109
2 + 108
3 + 107
4 + 106
(...)
106 + 4
107 + 3
108 + 2
109 + 1
There are 109 such pairs - unless you don't want to count the combinations of the same numbers but in different order (e.g. 50 + 60 and 60 + 50) - then there are 55 such pairs (up to 55 + 55).
You can also count 0 - sometimes we treat it as a whole number, sometimes we don't - then add two pairs (0 + 110 and 110 + 0) to the 109 pairs result, or 1 pair for 55 pairs result.
I hope it's quite understandable :)
Answer:
C. 18 cm
Step-by-step explanation:
The ratio of the sides of the triangle shown is 12 : 15 = 4 : 5. We know it is a right triangle, so we know the missing side length completes the ratio
3 : 4 : 5 = 9 : 12 : 15
Half of XY is 9 cm, so the length of the entire chord is 18 cm.
_____
The chord is tangent to the inner circle, so makes a 90° angle with the radius to that tangent point. This tells you that the triangle shown is a right triangle. It also tells you that the short radius bisects the chord. The Pythagorean theorem can be used to find the length of the side not shown (half the chord length).
The unknown side (a) can be found from ...
15² = 12² +a²
225 -144 = a² . . . . . . subtract 12²
81 = a² . . . . . . . . . . . simplify
9 = a . . . . . . . . . . . . . take the square root
The chord length is 2a, so is ...
2(9 cm) = 18 cm . . . . length of chord XY
Answer:c
Step-by-step explanation:
Answer:
3.333 if the equation is: 
Step-by-step explanation:
Looks like you are saying those are base logarithms.
I think you have the equation:

Use product rule, that is,
.

Both sides are the same except the insides. If we want the left hand side to be the same as the right hand side, then we need 3a and 10 to be the same.
When are those the same?
Set them equal and find out!
3a=10
Divide boht sides by 3:
a=10/3
Perform the division in your calculator:
10 division sign 3
gives you 3.333333333(repeating).