Question

lindsey is 5 years less than half of her fathers age. the sum of their ages is 79. how old is lindsey? create an equation and solve

Answer 1

`Let \: Lindsey's \: father's \: age \: be \: = \: x`

`Then \: Lindsey's \: age = (1)/(2) x - 5`

`Sum \: of \: their \: age = 79`

This can be written in an equation as :-

`x + (1)/(2) x - 5 = 79`

`To \: find \: out \: Lindsey's \: age \: , let \: us \: first \: find \: out \: the \: value \: of \: x .</p><p>`

`1 (1)/(2) x - 5 = 79`

`(3)/(2) x - 5 = 79`

`(3)/(2) x = 79 + 5`

`(3)/(2) x = 84`

`x = 84 / (3)/(2)`

`x = 84 * (2)/(3)`

`x = (168)/(3)`

`x = 56`

`Lindsey's \: father's \: age = 56`

`Lindsey's \: age = 28 - 5`

`Lindsey's \: age = 23`

∴Lindsey's age is 23 .