Here's a pattern to consider:
1+100=101
2+99=101
3+98=101
4+97=101
5+96=101
.....
This question relates to the discovery of Gauss, a mathematician. He found out that if you split 100 from 1-50 and 51-100, you could add them from each end to get a sum of 101. As there are 50 sets of addition, then the total is 50×101=5050
So, the sum of the first 100 positive integers is 5050.
Quick note
We can use a formula to find out the sum of an arithmetic series:
Where s is the sum of the series and n is the number of terms in the series. It works for the above problem.
you'll get a decimal format, just multiply it times 100, to get the % format
First you add up all the items and the coupon then you will get $24.51. then subtract $50.00 take away $24.51 then you will get $25.49. So when she left the store she had $25.49
Step-by-step explanation:
x2-8x-3x+24=0
x(x-8) 3(x+8)
(x-8)(x+8)
x-8=0 or x+8=0
x=8. x= -8
X/7 = 6/4.2
4.2x = 42
x= 10