we know the total amount invested is 8200, so if the first amount is say "a", the second amount must be the slack left from subtracting "a", namely b = 8200 - a.
we also know 13% of "a" plus 2% of "b" yielded an interest of $461 in a year.
The area of a square would me multiplying the width times the length and then multiplying by one half would be like splitting the square in half so your answer would be that last one right there. 6*6= area then multiply by 1/2 = half of area Hope this helps! :D