4 years ago, age of a mother was 3 times the age of her daughter. Write a linear equation to represent this situation and draw its graph.
present age of daughter be x years.
4 years ago age of daughter was (x - 4) years
Let present age of mother be y years.
∴ Mother’s age, 4 years ago = (y - 4) years
According to the question:
y - 4 = 3(x - 4)
⇒ y - 4 = 3x - 12
⇒ 3x - y = 8