Question

S10 Якщо a1=-2 ; a10=-50​

Answer 1

$\displaystyle\bf\\a_{1} =-2\\\\a_{10} =-50\\\\\\S_{10} =\frac{a_{1}+a_{10} }{2} \cdot 10=\bigg(a_{1} +a_{10} \bigg)\cdot 5=\bigg(-2-50\bigg)\cdot 5=-25\cdot 5=-125\\\\\\Otvet: \ S_{10}=-125$

Answer 2

Calculating the Common Difference in an Arithmetic Sequence

To find the common difference in an arithmetic sequence, we can use the formula:

Common Difference (d) = (a10 - a1) / 9

Given: - a1 = -2 - a10 = -50

Using the given values, we can calculate the common difference as follows:

Common Difference (d) = (-50 - (-2)) / 9 Common Difference (d) = (-50 + 2) / 9 Common Difference (d) = -48 / 9 Common Difference (d) = -5.33

So, the common difference (d) in this arithmetic sequence is -5.33.