Question

Plug in the values from the set {12, 15, 18, 19} to find the value of x. The value that holds true for the equation is . So, Jenny is years old and her mother is years old.

Answer 1

Jenny´s age is 19 and her mother is 43.

Explanation:

Given that

x + 2x + 5 = 62

where,

x = Jenny’s age

Now the following cases occured

a.

x = 12

Now put the x value to the above equation

12 + 2(12) + 5 = 62

12 + 24 + 5 = 62

41 = 62

It is not equaled so the Jenny age is not 12

b.

x = 15

Now put the x value to the above equation

12 + 2(15) + 5 = 62

15 + 30 + 5 = 62

50 = 62

It is not equaled so the Jenny age is not 15

c.

x = 18

Now put the x value to the above equation

18 + 2(18) + 5 = 62

18 + 36 + 5 = 62

59 = 62

It is not equaled so the Jenny age is not 12

d.

x = 19

Now put the x value to the above equation

19 + 2(19) + 5 = 62

19 + 38 + 5 = 62

62 = 62

It is equaled so the Jenny age is 19

Now the mother age is

as we know that

x + y = 62

19 + y = 62

y = 62 - 19

= 43

Also it proved that if we doubles the jenny age i.e 38 and then add 5 so the total is 43 i.e. equivalent to her mother age