Mirella4mg Mirella4mg

01-08-2016
Mathematics

contestada

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

Respuesta :

dalendrk dalendrk

01-08-2016

[tex]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}[/tex]

Answer Link

Otras preguntas

Carla's plant was 10 2/3 inches tall. Yolanda's was 8 3/4 inches tall. How much taller was Carla's plant than Yolanda's?I came up with 2 11/12. Am I right??

Show that n^2-1 is divisible by 8,if 'n' is an odd positive integer.

Acme Inc. spent $870 less on postage than on supplies. The ratio of postage costs to supply costs was 2 to 5. How much did Acme spend on postage? Solve this pro

Rheumatic fever is a bacterial disease that can result in degeneration of heart valves that would cause?

Noah rows across a river that is 48m wide. The current carries him 15m downstream. How far does Noah actually travel?

What is 3y = 15x - 12 in y = mx + b form ?

how do you multiply and divide equations?

True or false. If a line L1has equation y = mx + b, where m and b are constants with m ≠ 0, then an equation of a line L2 perpendicular to L1 has the form y = -

How did the aboriginals people heal themselves before Europeans arrives?

Help me please. What Is Stonehenge?