Question

a woman invested 4 times as much at 2% as she did at 5%. The total amount of interest she earns in 1 year from both accounts is $780. How much did she invest at each rate?

Answer 1

lets call the amount of money invested at 5% \(x\) so the amount invested at 2% is \(4x\)

Answer 2

then you know \(.02\times 4x+.05\times x=780\) or
\[.08x+.05x=780\] or even
\[.13x=780\] you good from there?

Answer 3

last step is \(x=780\div .13\) or \(x=78000\div13\)