Question 673179: Jenny is three times as old as her daughter Krystal. Four years ago she was four times as old as Krystal. How old is each now? Answer by rm29924(97) (Show Source):
You can put this solution on YOUR website! let x = Krystal's age now
Jenny is three times as old so Jenny's current age = 3x
Jenny's age 4 yrs ago = 3x - 4
Krystal's age 4 yrs ago = x-4
four years ago she was four times as old as Krystal
3x-4 = 4(x-4)
multiply by 4
3x-4 = 4x-16
add 16 to both sides
3x+12 = 4x
subtract 3x from both sides
12 = x
Krystal's age now is 12
Jenny's age now is 3(12) = 36
check work:
3x-4 = 4(x-4)
3(12)-4 = 4(12-4)
36-4 = 32
32=32
