How to plot One linear, one quadratic graph

Question:

(a) Draw the graph of  for values of x from -4 to 2

(b) Use the graph to solve the equations

                   

  ( c) By drawing the line  y = 2x + 1 on the same axes, solve the equation       

         

     

Solution

First find the values of y for every value of x. I will only calculate for few values of x to get their corresponding values of y. This part is very important and care need to be taken because any wrong value got will render all your effort useless. The calculation is simple substitution of the given values of x to the equation.  Just that, see below

 Below is the table of the calculation 

Calculate also for the line graph to get the table below. Same method of substitution.

Plot the graph as shown below

Follow the steps below the needed values from the graph