Your x and y intersection is: (-2,0).
Notice, ending ends makes it easeier
1+20=21
2+19=21
...
10+11=21
there are 10 pairs of numbers
they add to 21
10 times 21=210
the sum is 210
Answer:
7200
Step-by-step explanation:
You can also do it in your head. In the numbers 1000 1009, the only ones divisible by 5 are 1000 and 1005. This pattern repeats for every group of 10. So for every group of 10 there are 8 numbers not divisible by 5.
How many groups of ten are there in the 4 digit numbers? the first one is 1000 and the last one is 9999, so there are just 900 groups of 10. 900 * 8 is 7200, which is the same answer.
Or did you want it done with a formula?
