Gauss' method for addition relies on the fact that you can 'pair' certain numbers together. Look at the example:
1+2+3+4+5+6+7+8+9+10
We could manually add all these together from left to right but a clever way to think about this is if we add together the ends of the sum (10+1) we get 11. If we then move one in from the ends and add these (2+9) we also get 11. This means that 1+2+...+9+10 is the same as 11+11+...+11+11.
Because each 2 numbers adds to 11 we know the total number of 11's we have to add together is the length of the sum divided by 2. In our case 5 (10 ÷ 2). We need to add 5 lots of 11 to get our answer. This is the same as 11 × 5 which is easily seen to be 55.
(If you add the 10 numbers together on a calculator you'll see 1+2+3+4+5+6+7+8+9+10 = 55) so this method really makes it a lot quicker.
Looking at your sequence, if we pair the ends together we get 401 (400+1) and we multiply this by the length of the sequence divided by 2. In your case, 200 (400 ÷ 2).
So the sum of all the numbers from 1 to 400 must be 401 × 200 = 80,200.
Remember the steps:
1. Pair the ends together and add them
2. Times this number by the length of the sequence halved
Hope this helps.
Answer:
I think its 5 consecutive zeros.
Step-by-step explanation:
This would be a guess but I think you would need two numbers in the hundreds that also have 2 parts of which have a product of a number ending in 0, like 4 and 5.
So my guess would be
400 * 500 * 39
= 7800000
=12-5=7
=21-12=9
when u look at they have a diffrence of 2 so the answer will have a diffrence of 2 =11
Answer: They form a 90° angle
Answer:
Step-by-step explanation:
4*3^x+1=27+(3^2)^x
(3^2)^x=(3^x)^2
3^x=t
4t+1=27+t^2
t^2-4t+27-1=0
t^2-4t+26=0
delta=4^2-4*1*26=16-84=-68<0
the equation has not real solutions
