9514 1404 393
Answer:
14. (x, y) = (1, 3)
15. $6200
Explanation:
14. Substitution is a nice strategy for this one, since we have an expression for y. Using the second equation in the first, we get ...
4x +(2x+1) = 7
6x +1 = 7 . . . . . . . collect terms
6x = 6 . . . . . . . subtract 1
x = 1 . . . . . . . divide by 6
y = 2(1) +1 = 3 . . . . substitute for x in the second equation
The solution is (x, y) = (1, 3).
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15. The formula for the balance when the investment earns simple interest is ...
A = P(1 +rt)
where P is the principal invested, r is the annual rate, and t is the number of years.
For the given values, we find the account balance to be ...
A = $5000(1 +0.04·6) = $5000·1.24 = $6200
Jacob will have $6200 in his account after 6 years.