Answer:

Step-by-step explanation:
This book has 500 pages in total.
We should split up the place values.
1 - 9
One only appears once.
1
10 - 19
One appears 11 times.
1 + 11
20 - 99
One only appears 8 times.
1 + 11 + 8
Add:
1 + 11 + 8
=> 20
Since the same is for 200-299, and so on. Let us add twenty four times.
20 * 4
=> 80
Looking back to 100-199, there are 120 ones.
Add:
120 + 80
=> 200
Answer:
-1 + 2 = 1
1 + (-2) = -1
-1 - 2 = -3
1 - (-2) = 3
Step-by-step explanation
When you subtract use keep change change
Rule 1 when you add : If the signs are the same add the numbers and take the sign of the bigger number.
Rule 2 when you add : If the signs are different subtract the numbers and take the sign of the bigger number.
I wanted to help you understand and i hope i did that!
I believe it's a , not sure though
Answer: The answer is C
Step-by-step explanation: 15 - 2 = 13 13+5=18
Hope this helps :)
Answer: The answer is 13 ponds of each type should be used.
Step-by-step explanation: Given that the coffee counter charges $11.00 per pound for kenyan french roast coffee and $13.00 per pound for sumatra coffee. We are to find the quantity of each type that should be used to make a 26 pound blend that sells for $12.00 per pound.
Let 'x' pound and 'y' pound of kenyan french roast coffee and sumatra coffee be used in the mixture of 26 pound.
So, we have

Multiplying equation (A) by 11 and subtracting from equation (B), we have

and from equation (A),

Thus, 13 pounds of each type of coffee should be used.