The depth y (in inches) of a lake after x years is represented by the equation y=0.2x+42. How much does the depth of the lake increase in four years?

42.8 in
Step-by-step explanation:
Step one:
given data
we are told that the expression for the depth of a lake after x years is given by

Required
The value of y when x= 4
Step two:
substitute the value of x in the expression to get y

After 4 years the depth will increase by 42.8 in