Answer :
Let x represent the number of $10 traveler's checks she has.
Let y represent the number of $20 traveler's checks she has.
[tex]10x+20y=300 \\x+y=22[/tex]
Solve system of equations.
[tex]y=22-x \\10x+20(22-x)=300 \\10x+440-20x=300 \\140=10x \\x=14 \\y=22-14 \\y=8[/tex]
Let y represent the number of $20 traveler's checks she has.
[tex]10x+20y=300 \\x+y=22[/tex]
Solve system of equations.
[tex]y=22-x \\10x+20(22-x)=300 \\10x+440-20x=300 \\140=10x \\x=14 \\y=22-14 \\y=8[/tex]