Answer: Ms Smith invested $9,000 in one account and $16,000 in the second account
Step-by-step explanation:
Now let us denote the amount she invested in the first account by "a" and denote the amount she invested in the second account by "b".
If she invested $25,000 in the 2 accounts, then:
a + b = $25000 ------- call this equation (eqn)1
Again, the first account yielded extra 4% of what was invested.
Therefore 4/100 × a = 4a/100 (this is the amount the first account yielded)
The second account yielded extra 12% of the invested amount
Therefore 12%×b = 12b/100
If the total sum of the interest the 2 accounts yielded was 2280, then:
( 4a/100) + (12b/100) = 2280 -----let this be eqn 2
We now have simultaneous equations before us.
In eqn 1, making b the subject of the formula:
b = $25000 - a
Substitute b for $25000 - a in eqn 2
(4a/100) + [12(25000 - a)/100] = 2280
300000 - 8a = 228000
- 8a = 228000 - 300000
a = -72000/-8
a = $9000
Now, we substitute "a" for $9,000 in eqn 1
9000 + b = 25000
b = 25000 - 9000
b = $16,000
So, Ms Smith invested separate sums of $9,000 and $16000 in the two accounts
