Lindsay and her father like to attended concerts on Saturday afternoons. Lindsey is 5 years less than half her father's age. The sum of their ages is 79. How old is lindsey.

Answer 1

Lindsey's age + dads age= 79 years old

L + F = 79

So...

F =79 - L

L=79 - F

Lindsey is 5 years less than half of her father's age

L =(F/2) - 5

Substitute L for (79 - F)

79 - F = (F/2) - 5

Solve for F (fathers age)

79-F = (F/2) -5

+5. = +5

84 -F = F/2

+F = +F

84= 3F /2

×2/3= X2/3

56= F (fathers age is 56)

So L= 79-56 =23

(Daughters age is 23)

Answer 2

F = father's age

L= Lindsay's age = (F/2) - 5

F + L = 79

F + (F/2) - 5 = 79

3F/2 = 84

3F = 168

F = 56

L = 56/2 - 5 = 28 - 5 = 23

Check: 56 + 23 = 79!