a movie star did not want to tell his age so he told a newspaper "seven years ago I was eleven times as old as my daughter. Now I am four times as old as she is." how old is the star? (I know the anser is 40 but I don't know how to set up the equation! please help!
2006-08-29 16:32:13 · 3 answers · asked by smarin1987 2 in Education & Reference ➔ Higher Education (University +)
Let x equal the movie star's age and y equal the daughters age.
Then:
1.) x - 7 = 11*(y - 7)
2.) x = 4*y
Substitute (4*y) for x in 1:
(4*y) - 7 = 11*(y - 7)
Solve for y:
-7 = 11*y - 4*y - 77
70 = 7*y
y = 10
Use 2 to slove for x:
x = 4*y
x = 4*10
x = 40
2006-08-29 16:44:56 · answer #1 · answered by vintagejbass 3 · 0⤊ 0⤋
Alternatively you could plug in y=(x/4) into the above equation and solve directly for x.
2006-08-30 01:17:15 · answer #2 · answered by Victor H 1 · 0⤊ 0⤋
I can't really help,but here is this link ,you might find something helpful. I know how hard it is...I hate word problems!
Good luck!
2006-08-29 23:55:20 · answer #3 · answered by hedychambers 2 · 0⤊ 0⤋