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put this solution on YOUR website!anns age is seven-tenths of bills age.
a =

b
or
a = .7b
:
in 4 years anns age will be eight-elevenths of bills age.
a + 4 =

(b+4)
:
Replace a with .7b
.7b + 4 =

(b+4)
;
Multiply both sides by 11 to get rid of the annoying denominator
7.7b + 44 = 8(b+4)
;
7.7b + 44 = 8b + 32
:
44 - 32 = 8b - 7.7b
:
12 = .3b
b =

b = 40 yr is Bill
then
.7(40) = 28 yrs is Ann
:
:
Check solution in the statement:
"in 4 years anns age will be eight-elevenths of bills age"
32 =

*44