Answer:
1) -32+12x 2) 2(3x-4)
Step-by-step explanation:
I hope this is right!
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:
60%
Step-by-step explanation:
135-60%=54
so therefore the price fell to 54 and was 60% off!
Hope this helped!
Part A: Chose some value for x, that means any amount of books to print for example 100 books, so x=100
Replace x=100 in C(x) and solve:
C(100)=3.5*100+1200=1550
Part B: Replace C(x) by 1900 and solve for x from the given equation:
1900=3.5x+1200
3.5x=1900-1200
x=700/3.5= 200
Part C: the statement C(20)=1270 means that 1270 is the cost for printing 20 books.
Part E: C(40.5)=1341.75 I think this statement is incorrect given the context because x means number of books to print so this value must be an integer number.
