Answer:
<em>Cathy was born in 1980 and she was 18 years old in 1998</em>
Step-by-step explanation:
<u>Equations</u>
This is a special type of equations where all the unknowns must be integers and limited to a range [0,9] because they are the digits of a number.
Let's say Cathy was born in the year x formed by the ordered digits abcd. A number expressed by its digits can be calculated as

In 1998, Cathy's age was

And it must be equal to the sum of the four digits

Rearranging

We are sure a=1, b=9 because Cathy's age is limited to having been born in the same century and millennium. Thus

Operating

If now we try some values for c we notice there is only one possible valid combination, since c and d must be integers in the range [0,9]
c=8, d=0
Thus, Cathy was born in 1980 and she was 18 years old in 1998. Note that 1+9+8+0=18
It would stop at 3y+4>11 because the 3y and 4 are unlike terms and can only be divided or multiplied.
Answer:
False
Step-by-step explanation:
The surface area of the cone is




The surface area of the cylinder is:



Answer:
Step-by-step explanation:
The answer is actually
Let:
S=1+2+3+4+5+6+7+8+9+n
We know the answer to the following infinite sum:
S2=1-1+1-1+1-1+1-1+1-1+1-1+1-....= - 1/2
We can therefore solve for this sum:
S3=1-2+3-4+5-6+7-8+9-....
We add them:
S3= 1-2+3-4+5-6+7-8...
S3= +1-2+3-4+5-6+7-8...
________________
2S3= 1-1+1-1+1-1+1-1+1-....
Therefore:
2S3=S2=
Answer: (16,O0) That is 16 to positive infinity
Step-by-step explanation:
4.5x - 9.5 > 62.5
4.5x > 62,5 + 9.5
4.5x > 72
x > 72/ 4.5
x> 16
So all real numbers greater than 16 is the solution set.
(16,O0)
I wish I had the infinity symbol on this keyboard!