math
posted by gary .
A. A woman was 30 years old when her daughter was born.Her age is now 6 years more than three times her daughter's age. How old will the daughter be in 5 years?
B. Lisa is 15 years old and her father is 40. How many years ago was the father six times as old as Lisa?
C. Joel is one third the age of Bob. In 7 years the combined ages of the boys will be 58. How old is each boy now?
D. Tom is three times as old as Leigh Ann. In 7 years, the sum of half of Tom's present age and a third of Leigh Ann's age will be the same as Tom's age now. How old will Tom be in 7 years?

A.
n years ago, daughter was born. So now mother is n+30 and daughter is n
n+30 = 3n+6
n = 12
In 5 years daughter will be 17
B.
n years ago
6(15n) = 40n
n = 10
C.
3j=b
j+7+b+7=58
4j=44
j=11
b=33
D.
t=3a
t/2 + (a+7)/3 = t
3a/2 + (a+7)/3 = 3a
9a + 2a+14 = 18a
a = 2
t+7 = 13