Question 355198
Let {{{A}}} be the amount invested at 7%, {{{B}}} the amount at 5%.
Total amount invested:
1.{{{A+B=22000}}}
Total interest obtained:
2.{{{7A+5B=142000}}}
Multiply eq. 1 by (-5) and add to eq. 2 to eliminate {{{B}}} and solve for {{{A}}}.
{{{-5A-5B+7A+5B=-110000+142000}}}
{{{2A=32000}}}
{{{highlight(A=16000)}}}
Then from eq. 1,
{{{16000+B=22000}}}
{{{highlight(B=6000)}}}