Question

the sum of three consecutive terms in an arithmetic sequence is 30, and their product is 360.
Find the three terms.
Let x denote the middle term and d the common difference.

well i got so far:

______+________+__________= 30
but
______x________x__________=360

ya, thats as far as I got and i am still stumped. I tried all kinds of things but i cant seem to get the right sum and multiplied values

Answer 1

middle term must be 10

Answer 2

do i divide by 36? how do i know what to put in for the middle parts? i remember class mates saying something by going up or down by a k, or a 1 or something. is there a rule or something like that I have to know?

Answer 3

ok, using your notation, x is the middle term, d is the common difference:
(x-d) + x + (x+d) = 30.
so what's x?

Answer 4

okay so the the left would be negative and the right would be positive.

Answer 5

okay @cnknd would it be
10-5 + 10 + 10+5 = 30?

Answer 6

ugh... what????
ok take a step back, forget i told u that middle term is 10.
look at the equation for the sum:
(x-d) + x + (x+d) = 30
can u find x and d from this?

Answer 7

okay well i was thinking the 30/3 = the 10

Answer 8

@cnknd
okay the d is the difference and x is the actual number.

i am lost as to where to start

Answer 9

(x-d) + x + (x+d) = 30
can you solve for either x or d?

Answer 10

i think we can solve the x.
the 3x= 30 so x=10, right?

Answer 11

yes
but you can't really determine what d is though.

Answer 12

but at least now you know why the x (the middle number) is 10.

Answer 13

you can probably guess and check for the other 2 numbers (that's what i did)

Answer 14

okay, let me try and ill get back to you on this in a little

Answer 15

GOT IT!
(10-8) +/* 10 +/* (10+8) +=30 * =360

Answer 16

THANK YOU SO MUCH @cnknd