A washer and a dryer cost $790 combined. The washer costs $40 more than the dryer. What is the cost of the dryer?

if the washer and dryer cost $790 then you would divide 790 by 2.

then you will get $395

then you add 40 to $395 and will get $435

so the answer is $435

step-by-step explanation:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for