Mrs.roberts is 3 times as old as her son.the sum of thier ages is 48 years.how old was mrs. roberts when her son was vactions

Respuesta :

Mrs Roberts = x
Son = y

x = 3y
x + y = 48 Put 3y in for x
3y + y = 48
4y = 48
y = 12 Son's age.

Therefore Mrs Roberts = 3*12 = 36