Since she bought 4 bags of 50 beads and 3 bags of 200 beads you only need to use two operations: multiply and add.
4 x 50 is 200
3 x 200 is 600
600 + 200 = 800
Mariah purchase 800 beads in total.
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.
Answer: 75-watt are 30$ fluorescent are 30$ in the second and 65$ in the first
Step-by-step explanation: i calculated thirty 75-watt and the fluorescent and got these kinda hard to explain hope i helped:)
Answer:
2 – 3х + 5х = 16 — 8х + 8x
2 - 8x = 16
8x = 14,
x = 1.75