Answer:
(c)
and

(d)

Explanation:
Given
See attachment
First, we complete the table





So, we have:

Solving (c): Between which values is y
The values of y are for both equations are closest at:
and

Hence, the solution is between
and

Solving (d): Approximated value of the solution
We have:



So:

Collect like terms


Divide both sides by 3

Substitute
in



So, the solution is:
