denise is 6 years older than her sister. 8 years ago she was 4 times as old as her sister how old is each girl now

Denise = 16

Sister = 10

Step-by-step explanation:

D=denise

S=sister

Eq 1)   D=S+6

Eq 2)  D-8 =4S-8

replace D with S+6 in Eq 2

(S+6)-8 = 4S -8

S-2 = 4S -8

add 8 to both sides

S+6 =4S

subtract S from both sides

6 = 3S

divide both sides by 3

2 = S   ( this is the sister age 8 years ago )

2+8 = 10  current age

plug that into Eq 1)

D = 10 +6

D=16    (Denise's current age)

so

Denise = 16

Sister = 10

if you subtract 8 from each , then there ages 8 years ago would be

Denise =8

Sister = 2

and 2*4 = 8  

this checks