3 years ago

The third term of an arithmetic sequence is 21, and the eighth term is 56. The first term is

1 answer:

5 0

$a_3=21;\ a_8=56\\\\a_8-a_3=5d\\\\5d=56-21\\5d=35\ \ \ |divide\ both\ sides\ by\ 5\\d=7\\\\a_1=a_3-2d\\\\a_1=21-2\cdot7\\a_1=21-14\\a_1=7\\\\Answer:\boxed{a_1=7}$

You might be interested in

5.Joan Robinson opens her own law office on July 1, 2012. During the first month of operations, the following transactions occur

Mademuasel [1]

Step-by-step explanation:

i will go you in the bank in co2 in the man

5 0

2 years ago

What is the product of d – 9 and 2d2 11d – 4? 2d3 – 7d2 – 103d 36 2d3 – 7d2 – 95d 36 2d3 7d2 – 95d 36 2d3 7d2 – 103d 36.

Mice21 [21]

The product of algebraic expression is $\rm 2d^3 - 7d^2- 103d + 36$ .

We have to determine

What is the product of d - 9 and 2d^2+11d-4?

<h3>How to find the product of two algebraic expressions?</h3>

The product of the algebraic expressions is also an algebraic expression. Lastly, simplify the algebraic expression by the fundamental operations of terms for combining the like terms.

Therefore,

The product of algebraic expression is;

$\rm = (d - 9) \times (2d^2 + 11d - 4)\\\\= d (2d^2 + 11d - 4)-9 (2d^2 + 11d - 4)\\\\= 2d^3+11d^2-4d-18d^2-99d+36\\\\=2d^3 - 7d^2- 103d + 36$