First term: a1 = 151
common difference: d = -14 (we decrease by 14 each time, eg, 151-14 = 137)
nth term of this arithmetic sequence is...
an = a1+d(n-1)
an = 151+(-14)(n-1)
an = 151-14n+14
an = -14n+165
This will be used in the formula below
Sn = n*(a1+an)/2
<span>Sn = n*(151+(-14n+165))/2
</span><span>S26 = 26*(151+(-14*26+165))/2 ... replace every n with 26
</span>S26 = -624
The final answer here is choice C) -624
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Answer:
Step-by-step explanation:
The student currently has $50 and plans to save $15 every month.
Let x represent the number of months that the student will save enough money to buy the microscope.
Let y represent the amount that the student saves after x months.
The function that represents the amount y (in dollars) of money that the student saves after x months will be
y = 50 + 15x
The 50 remains constant because she has already saved it
Answer:
Answer
2x+3y=14,2x−3y=2
Adding :
2x+3y=14
2x−3y=2
__________
4x=16
x=4
∴xy=4×2
=8
2×4+3y=14
8+3y=14
3y=6
y=2
Step-by-step explanation:
here you go
Answer:
They use 741 dollars
Step-by-step explanation:
Write 65% as
65/100
Since, finding the fraction of a number is same as multiplying the fraction with the number, we have
65/100 of 1140 = 65/100× 1140
Therefore, the answer is 741
If you are using a calculator, simply enter 65÷100×1140 which will give you 741 as the answer.