how much did she invest at 5 %?
2007-01-21 06:21:34 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
This is a simple system of equations. Let x be the amount invested at 5%, and y the amount invested at 3%. Then
x + y = $30,000
and
.05x + .03y = $1120
Solve the first equation for y:
y = 30000 - x
Then plug it into the second equation:
.05x + .03 * (30000 - x) = 1120
.05x + 900 - .03x = 1120
.02x = 220
x = 11000
Since x represents the amount invested at 5%, $11,000 was invested at this rate. If you had instead solved for y, you would have had the amount invested at 3%, and would subtract that amount from $30,000, and should once again get $11,000.
2007-01-21 06:35:53 · answer #1 · answered by Dan 3 · 0⤊ 0⤋
I believe you need to put this in 2 equations:
1) x + y = 30,000
2) 0,05x + 0,03y = 1,120
And then solve for x like so:
0,05x + 0,03(30,000 - x) = 1,120
and so on
2007-01-21 14:30:57 · answer #2 · answered by AH 3 · 0⤊ 0⤋
5/100 *x + 3/100 *y = 1,120
x+y=30,000
5x +3y= 112,000
y= 30,000-x
5x +90,000 -3x =112,000
2x= 22,000 x=$11,000 invested at 5%
2007-01-21 14:53:51 · answer #3 · answered by santmann2002 7 · 0⤊ 0⤋
She invested 11,000 at 5% and 19,000 at 3%
2007-01-21 14:30:14 · answer #4 · answered by michael45672007 3 · 0⤊ 0⤋
11,000 dollars at 5%
19,000 dollars at 3%
11,000(.05) = $550.00
19,000(.03) = $570.00
550 + 570 = 1120.00
2007-01-21 14:38:22 · answer #5 · answered by billy_0_69 2 · 0⤊ 0⤋