Marys father is four times as old as Mary' Five years ago he was seven times as old' How old is each

1
Marys father is four times as old as Mary. Five
years ago he was seven times as old. How old is
each now?
The first fact is Marys father is 4 times as old
as Mary. So, Let x Marys age now 4x
fathers age now
The second fact is that 5 years ago . . . (stop!)
The problem is now talking about another time,
so x 5 Marys age 5 years ago 4x 5
fathers age 5 years ago
4x 5 7(x-5)
2
Abigail is 6 years older than Jonathan. Six
years ago she was twice as old as him. How old
is each now?
x Jonathans age now x 6 Abigails age
now Six years ago, x 6 Jonathans age (x6)
6 Abigails age
(x 6) 6 2(x - 6)
3
Zac is 10 years older than Zelda. Twelve years
ago he was twice as old as Zelda. How old is
each now?
Zelda x
Zac x 10
12 years earlier
Zelda (x 12)
Zac (x 10) - 12