1487 base nine + 3825 base nine

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

The area of square garden is 300m squared. how long is the diagonal?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?