One year ago liz was three times as old as her brother jack. in two years she'll be only twice as old as jack. how old are liz and jack now?

L = liz's age now

J = Jack's age now

L-1 and J-1 are their ages one year ago

L-1=3(J-1)

L-1=3J-3

L=3J-3+1

L=3J-2 (to be used later)

L+2 and J+2 are their ages in two years

L+2=2(J+2)

replace L by 3J-2

3J-2+2=2(J+2)

3J=2J+4

3J-2J=4

J=4 is Jack's age now

L-1=3(J-1)

L-1=3(4-1)

L-1=3*3

L-1=9

L=9+1

L=10 is Liz's age now

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right