Question

Every six months, price of petrol increases at the rate of Rs.4 per litre. Taking price of petrol in December, 2011 as x and present price of petrol as y, from a linear equation showing amount spent on petrol in December, 2012.

Answer 1

A linear equation is of the form:

y = mx + c


y = dependent variable
x = independent variable
m = rate
c = constant



In this case:

y = present price of petrol
x = Number of years = 1
m = Rs.4 per litre
c = x, price of petrol in December, 2011



Therefore:
y = 4(1) + x

y = x + 4

Answer 2

Answer:

y=x+8 is the answer