Math 12 help please series and sequence pleasre show me your work im esperate for your help plz?

Question

1. For the three summer months (12 weeks), Job A pays $325 per month with a monthly raise of $100. Job B pays $50 per week with a weekly raise of $10. Which is the better paying job?
2. In a supermarket, cans of apple juice are displayed in a pyramid containng 12, 11, 10,..5 cans. How many cans are displayed?
3. Tasty Treats finds that its profit from he sale of ice cream increases by $5 per week during the 15 week summer season. If the profit for the first week is $30, find the profit for the season.
4. The sum of the first 5 terms of an arithmetic series is 85 and the sum of the first 6 terms is 123. Write the first 3 terms of the series.
Than k you

Answer 1

1) for jobs total salary is an A.P
A Total=(3/2)(2*325 +(3-1)*100 )=1275
B Total=(12/2)(2*50+(12-1)*10)=1260
job A is better

2) this is also A.P .we have to find the n.given a=12,d= -1 and
an(last term)=5
an=a+(n-1)d
5=12+(n-1) *-1
-7= 1-n
n=8 cans
3)a=30 d=5 n=15
total profit=(15/2)(2*30+(15-1)*5)=
4) (5/2)(2a+(5-1)d)=85
2a+4d=34
(6/2)(2a+(6-1)d)=123
2a+5d=41
subtracting these we get d=7
2a+28=34
2a=6
a=3
3,10,17

Answer 2

Answer for #1:

Job A: 4 weeks @ $325 + 4 weeks @ $425 + 4 weeks @ $525 = $1,275 for 3 months

Job B: Week 1 @ $50 + Week 2 @ $60 + Week 3 @ $70 + Week 4 @ $80 + Week 5 @ $90 + Week 6 @ $100 + Week 7 @ $110 + Week 8 @ $120 + Week 9 @ $130 + Week 10 @ $140 + Week 11 @ $150 + Week 12 @ $160 = $1,260 for 3 months.

Job A would be the better paying job.

Answer for #2:

Pyramid = 12+11+10+9+8+7+6+5=68 cans displayed

Answer 3

Job A pays 325+425+525 = $1275
Job B pays 210*6 =$1260
Job A is better
(12+5)*4 = 68

30 +35+40 +...+ 95 + 100
= 30 +135*7 = $975

d= 123-85 = 38
So 3rd term = 85-76= 9
2nd term = 9-38 = -29
1st term = -29-38=-67