Consider the linear equation 5x−7=13.
a. (i) Define what is meant by the solution of a linear equation in one variable.
b. (ii) Check whether x=4 is a solution of the equation 5x−7=13, showing each step of your working clearly.
c. (iii) Explain, in not more than three sentences, why it is necessary to carry out such a check after solving any linear equation.