Answer: Hello there!
"Garrett has one dollar less than three times as much money as Liz has"
If we define G as the amount of money that has Garret and L as the amount of money that Liz has, then:
3L - G = $1
and "together they have $175 "
L + G = $175
Now we want to know how much money Garrett has:
We could isolate L in the second equation:
L = $175 - G
Now we have L written in terms of G, and we can replace it in the first equation.
3L - G = $1
3*($175 - G) - G = $1
$525 - 4G = $1
4G = $525 - $1 = $524
G = $524/4 = $131
So Garret has 131 dollars, and you can replace it in the first equation (or the second) and get how much money Liz has:
$131 +G = $175
G = $175 - $131 = $44