she deposited two amounts, let's say "a" and "b"
"a" earning 2% interest
"b" earning 2.5% interest
the 2.5% one, is twice as much as the 2% one
so.. one can say that, whatever "a" is, "b" is twice as much,
or b = 2*a -> b = 2a
now.. .the sum of both earned interest, was $1190
so.. one can say that (2% of a) + (2.5% of b) = 1190
let' us use the decimal notation then
[tex]\frac{2}{100}a+\frac{2.5}{100}b=1190\implies 0.02a+0.025b=1190
\\ \quad \\
\textit{however, we know "b" is 2a thus}
\\ \quad \\
0.02a+0.025\boxed{b}=1190\implies 0.02a+0.025(\boxed{2a})=1190[/tex]
solve for "a" to find what the "a" amount is,
to find "b", well, "b" is "2a", so just do a 2*a to get "b"
