Steven needs a total of 320 points to have a mean score of 80
Steven has 245 points so far
Steven needs to score at least 75 points on his last test to qualify for the team
Answer:
D is the correct answer
Step-by-step explanation:
I just took the test
Answer:
Step-by-step explanation:
The formula for determining the sum of the first n terms of an arithmetic sequence is expressed as
Sn = n/2[2a + (n - 1)d]
Where
n represents the number of terms in the arithmetic sequence.
d represents the common difference of the terms in the arithmetic sequence.
a represents the first term of the arithmetic sequence.
If a = 5, the expression for the sum of the first 12 terms is
S12 = 12/2[2 × 5 + (12 - 1)d]
S12 = 6[10 + 11d]
S12 = 60 + 66d
Also, the expression for the sum of the first 3 terms is
S3 = 3/2[2 × 5 + (3 - 1)d]
S3 = 1.5[10 + 2d]
S3 = 15 + 3d
The sum of the first 12 terms is equal to ten times the sum of the first 3 terms. Therefore,
60 + 66d = 10(15 + 3d)
60 + 66d = 150 + 30d
66d + 30d = 150 - 60
36d = 90
d = 90/36
d = 2.5
For S20,
S20 = 20/2[2 × 5 + (20 - 1)2.5]
S20 = 10[10 + 47.5)
S20 = 10 × 57.5 = 575
For this case we can propose a system of equations:
x: Let the variable that represents the number of small cookies
y: Let the variable that represents the number of large cookies
According to the statement we have:

We multiply the first equation by -2:

We have the following equivalent system:

We add the equations:

We look for the value of the variable "x":

Answer:
They sold 80 small cookies and 50 large cookies
Answer: 1 and 4
Step-by-step explanation: just did it