Answer:

Step-by-step explanation:
The expression in the square root should be greater than or equal to zero, because square root of a negative number does not give a real number.

So... let's say the amounts invested were "a" at 6% and "b" at 7.5%.
ok.. hmm what's 6% of a? well, (6/100) * a or 0.06a.
what's 7.5% of b? well, (7.5/100) * b or 0.075b.
now... we know, whatever "a" and "b" are, they total the investment of 5000 bucks, thus
a + b = 5000and the interest yielded was 337.50, thus
0.06a + 0.075b = 337.50thus

solve for "a", to see how much was invested at 6%.
what about "b"? well, b = 5000 - a.
20% = 0.20.2 * 1630 = 326