Question 198412
Let {{{a}}}= amount invested @ 4%
Let {{{b}}}= amount invested @ 2.25%
{{{.04a + .0225b = 970}}}
Multiply both sides by {{{10000}}}
(1) {{{400a + 225b = 9700000}}}
{{{a + b = 33000}}}
Multiply both sides by {{{225}}}
(2) {{{225a + 225b = 7425000}}}
Subtract (2) from (1)
(1) {{{400a + 225b = 9700000}}}
(2) {{{-225a - 225b = -7425000}}}
{{{175a = 2275000}}}
{{{a = 13000}}}
And, since
{{{a + b = 33000}}}
{{{13000 + b = 33000}}}
{{{b = 20000}}}
She invested $13,000 @ 4% and $20,000 @ 2.25%
check:
{{{.04a + .0225b = 970}}}
{{{.04*13000 + .0225*20000 = 970}}}
{{{520 + 450 = 970}}}
{{{970 = 970}}}
OK