Answer:
The total period should be 14 months and not 141414 months.
Thus answer will be: number of months spent in Brazil is 5 months and he spent 9 months in Portugal.
Step-by-step explanation:
Let the number of months he lived in Portugal be X and the number of months he lived in Brazil be Y: Thus we have:
X + Y = 14 months.
He learned an average of 130 new words per month when he lived in Portugal: 130 x number of months (X) = 130X
and an average of 150 new words per month when he lived in Brazil: 150 x number of months in Brazil (Y) = 150Y.
Thus we have 130X + 150Y = 1920
Since X + Y = 14: make X subject of formula: X = 14 - Y. then substitute this for X in the equation below
130X + 150Y = 1920
130(14-Y) + 150Y = 1920
1820 - 130Y + 150Y = 1920
150Y - 130Y = 1920 - 1820
20Y = 100
Y = 100/ 20 = 5 months
Thus number of months spent in Brazil is 5 months. To find the number of months spent in portugal, use the first equation:
X + Y = 14 where Y is 5
X = 14 - 5 = 9 months. Thus he spent 9 months in Portugal