Question

A15= - 208 d= - 7 Знайти a1

Answer 1

Ответ:

an=a1+d(n-1)

a1=an-d(n-1)

n=45

a45=-208

d=-7

a1=-208-(-7)(45-1)

a1=-208+7*44=-208+308

a1=100

Объяснение:

Answer 2

To find the value of "a1" in the given sequence A15 = -208 and d = -7, you can use the formula for the nth term of an arithmetic sequence:

a_n = a1 + (n - 1) * d

Here, A15 is the 15th term of the sequence, so you can plug in the values:

A15 = a1 + (15 - 1) * (-7)

A15 = a1 + 14 * (-7)

Now, you need to solve for "a1." Start by rearranging the equation:

a1 = A15 - 14 * (-7)

Now, substitute the value of A15:

a1 = (-208) - 14 * (-7)

a1 = (-208) + 98

a1 = -110

So, the value of a1 is -110.