Answer:
Step-by-step explanation:
a1 = 3(1) - 7 = - 4
a2 = 3(2) - 7 = -1
d = a2 - a1
d = -1 - (-4)
d = -1 + 4
d = 3
a60 = 3(60) - 7
a60 = 180 - 7
a60 = 173
n = 60
Sum = (a1 + a60) * n / 2
Sum = (-4 + 173) * 60/2
Sum = (169)*30
Sum = 5070
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Just to check, we'll use the second summation formula
d = 3
n = 60
a1 = -4
Sum = (2*a1 + (n - 1)*d )*n / 2
Sum = (2*(-4) + (60 -1)*3)* 60/2
Sum = (-8 + 59*3) * 30
Sum = (177 - 8)*30
Sum = 169 * 30
Sum = 5070
Same answer.
Answer:
A,C,D
Step-by-step explanation:
The only one you might use it the triangle
Math uses numbers and equations, and science requires the scientific method and experimentation
Answer:
x + y = 13
98x + 115y = z
Step-by-step explanation:
Let x represent the time spent taking class in Westside community college
Let y represent the time spent taking class in Pinewood community college
Let z represent the combined total amount paid for the class fees.
The total combined time for the two school is given as:
x + y = 13.
For the combined total amount; we multiply the price for each school with the time spent on the school and sum them together.
Westside: 
Pinewood: 
The combined total amount represented as z is given as:
z = 98x + 115y