Question

Can anyone please help with this

Answer 1

Let us say hmm
p = months in Portugal
b = months in Brazil

Wolfrich learned 130 words in portugal, every month, so if he lived there 1 month, he got 130*p or 130*1 or 130 words only
two months, 130*2 or 260 words
three months 130*3 or 390 words and so on

so... if he lived only "p" months, he learned then, 130 * p, or 130p

in Brazil, he learned 150 monthly, same as before, if he lived "b" months, then he learned 150 * b, or 150b

he spent a total of 14 months on both places
so.. .whatever "b" is, and whatever "p" is, we know that
b + p = 14

and he learned a total of 1920 words
so... whatever 150b is, and whatever 130p is, we know that
150b + 130p = 1920

thus   $\bf \begin{cases} b+p=14\to \boxed{p}=14-b\\ 150b+130p=1920\\ ----------\\ 150b+130\left( \boxed{14-b} \right)=1920 \end{cases}$

solve for "b", to see how long he spent in Brazil

what about in Portugal?  well, p = 14 - b

Answer 2

About 3 in a half years I think