Question

A¹⁰=9,d=5, a¹-? help​

Answer 1

Дано:

a10=9

d=5

Найти: a1

an=a1+d(n-1)

a1=an-d(n-1)

a1=9-5*9

a1=9-45

a1=-36

Ответ: a1=-36

Answer 2

Ответ который вы задали будет: -36

Answer 3

It looks like you're trying to find the value of "a¹⁻" when "a¹⁰" is given as 9 and "d" is 5. In this context, it seems like you might be working with a geometric progression or sequence. The formula for finding the nth term of a geometric sequence is:

aⁿ = a¹ * (r^(n-1))

Where:

• aⁿ is the nth term
• a¹ is the first term
• r is the common ratio
• n is the term number

In your case, "a¹⁰" is given as 9, and "d" (common ratio) is given as 5. You want to find "a¹⁻". To find "a¹⁻," you need to rearrange the formula and solve for it:

aⁿ = a¹ * (r^(n-1))

a¹⁰ = a¹ * (5^(10-1))

9 = a¹ * (5^9)

Now, solve for "a¹" (the first term):

a¹ = 9 / (5^9)

Now that you've found "a¹," you can find "a¹⁻" using the same formula with n = -1:

a⁻¹ = a¹ * (5^(-1-1))

a⁻¹ = a¹ * (5^(-2))

To find "a⁻¹," you can substitute the value of "a¹" into the equation:

a⁻¹ = (9 / (5^9)) * (1 / (5^2))

a⁻¹ = (9 / (5^9)) * (1 / 25)

Now, you can calculate the value of "a⁻¹" using this expression.