In prima zi , un automobil a parcurs 70 de km mai putindecat in ziua a doua . In ziua a treia a parcurs cu 20 km mai mult decat in ziua a doua . In trei zile automobilul a parcurs in total 1300km . Ce distanta a parcurs in fiecare zi ?

250

step-by-step explanation:

(23*2)-12=x     x=34

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