Jill's present age is 3 less than twice Jack's age 2 years from now. However, 3 times Jack's present age is 9 more than Jill's age 2 years ago. What are their present ages?
Let x be Jack's age now and y be Jill's age now....and we know that :
y + 3 = 2 [ x + 2] → y = 2x +1 (1)
3x - 9 = y - 2 → y = 3x - 7 (2)
Set (1) = (2)
2x + 1 = 3x - 7 add 7 to both sides, subtract 2x from both sides]
8 = x and this is Jack's age now and Jill's age = 2(8) + 1 = 17
Let x be Jack's age now and y be Jill's age now....and we know that :
y + 3 = 2 [ x + 2] → y = 2x +1 (1)
3x - 9 = y - 2 → y = 3x - 7 (2)
Set (1) = (2)
2x + 1 = 3x - 7 add 7 to both sides, subtract 2x from both sides]
8 = x and this is Jack's age now and Jill's age = 2(8) + 1 = 17