Answer:
Learning task 2:
1. 37, 112
2. 11, 14
3. 12
Solution:
An = - 24
A1 = 9
n =?
d = -3
An = A1 + (n-1) d
-24 = 9 + (n-1) - 3
-24 = 9 + -3n + 3
-24 = 12 - 3n
-12 - 24 = -3n
-36 = -3n
-3 = -3
12 = n
4. 225
Solution:
a1 = 1
n = 15
d = 2
Sn = n/2 [ 2a1 + ( n - 1) d]
S15 = 15/2 [ 2(1) + (15 - 1) 2]
= 15/2 [ 2 + (14) 2]
= 15/2 (2 + 28)
= 15/2 (30)
= 15 x 30 / 2
= 450 / 2
S15 = 225
5. Solution:
A1 = 100
n =?
d = 100
An = 1000
An = A1 + ( n - 1 ) d
1000 = 100 + ( n - 1) 100
1000 = 100 + 100n - 100
1000 = 100n + 100 - 100
1000 = 100n
100 = 100
10 = n
Month of December
Save of jacob for 10 months
A1 = 100
n = 10
d = 100
Sn = n/2 [ 2a1 + ( n - 1) d]
= 10/2 [ 2(100) + ( 10 - 1 ) 100]
= 5 [ 200 + (9) 100]
= 5 ( 200 + 900)
= 5 (1100)
= 5, 550
Learning task 3:
1.
A.
An = 40
A1 = 10
d = 2
n =?
An = A1 + (n - 1 ) d
40 = 10 + ( n - 1 ) 2
40 = 10 + 2n - 2
40 - 10 + 2 = 2n
32 = 2n
2 = 2
16 = n
16th row
B.
A1 = 10
d = 2
n = 7
An = ?
An = A1 + ( n - 1 ) d
= 10 + ( 7 - 1) 2
= 10 + (6) 2
= 10 + 12
An = 22
In 7th row we have 22 seats
C.
A1 = 10
n = 24
d = 2
Sn = n/2 [ 2a1 + ( n - 1) d]
= 24 / 2 [ 2(10) + ( 24 - 1) 2]
= 12 [ 20 + ( 23 )2]
= 12 ( 20 + 46)
= 12 (66)
Sn = 792
There are 792 seats in a theatre
Rules: Since the highest row is 24 then this the value of n, next see the given to know what is your 1st term or A1, and next understand what is the common difference in the given and use it for the value of d, lastly compute all given number to get the answer or the Sum of arithmetic Sequence (Sn)
2.
A.
A1 = 3000 Pesos
d = 300 Pesos
n = 7 Months
An =?
An = A1 + (n - 1) d
= 3000 + ( 7 - 1 ) 300
= 3000 + (6) 300
= 3000 + 1800
An = 4800 Pesos
In month 7 his son received 4, 800 Pesos
B.
A1 = 3000 Pesos
n = 10 Months
d = 300 Pesos
An = ?
An = A1 + (n - 1) d
= 3000 + (10-1) 300
= 3000 + (9) 300
= 3000 + 2700
An = 5,700 Pesos
In month 10 his son received 5, 700 Pesos
Rules : to get the monthly Allowance identify your
1st term (A1) in the given, then identify the common difference (d) in the given, if the common difference is not given, no worry because we can find the common difference in general equation or the arithmetic sequence equation, then Understand what data needed to solve for easier way. Lastly use the arithmetic sequence equation to solve the problem involving the real life situation.
Learning Task 4:
1. 5, 9, 14, 19 not 20, 24
Letter A.
2. A
3. B
4. B
5. C
I hope makatulong ng malaki
