The amount invested at 4% is $4,333.33
The amount invested at 7% is $8,666.67
What represents the amount invested at 4%?
Let assume that x is the amount invested in the bank certificate of deposit (CD account) which earns 4%, in essence, the interest earned at 4% is the amount of money invested multiplied by 4%
interest at 4%=4%*x=0.04x
amount invested at 7%=13000-x
interest at 7%=7%*(13000-x)
interest at 7%=910-0.07x
total interest=0.04x+910-0.07x
total interest=910-0.03x
total interest earned=780
780=910-0.03x
0.03x=910-780
0.03x=130
x=130/0.03
x=amount invested at 4%=$4,333.33
amount invested at 7%=$13,000-$4,333.33
amount invested at 7%=$8,666.67
Find out more about multiple investment accounts on:https://brainly.com/question/2140799
#SPJ1