Give the geometric representations of $2x + 9 = 0$ as an equation
$(i)$ in one variable
$(ii)$ in two variables

Which one of the following options is true,and why?
$y = 3x + 5$ has
$(i)$ a unique solution,
$(ii)$ only two solutions,
$(iii)$ infinitely many solutions

In countries like $USA$ and Canada,temperature is measured in Fahrenheit,whereas in countries like India,it is measured in Celsius. Here is a linear equation that converts Fahrenheit to Celsius:
$F = \left(\frac{9}{5}\right) C + 32$
$(i)$ Draw the graph of the linear equation above using Celsius for $x$-axis and Fahrenheit for $y$-axis.
$(ii)$ If the temperature is $30\,^oC$,what is the temperature in Fahrenheit?
$(iii)$ If the temperature is $95\,^oF$,what is the temperature in Celsius?
$(iv)$ If the temperature is $0\,^oC$,what is the temperature in Fahrenheit and if the temperature is $0\,^oF$,what is the temperature in Celsius?
$(v)$ Is there a temperature which is numerically the same in both Fahrenheit and Celsius? If yes,find it.

Check whether $(4, 0)$ is a solution of the equation $x - 2y = 4$.

For each of the graphs given in the figure,select the equation whose graph it is from the choices given below:
$(a)$ For Fig. $(i)$,
$(i)$ $x+y=0$ (ii) $y=2x$ (iii) $y=x$ (iv) $y=2x+1$
$(b)$ For Fig. (ii),
$(i)$ $x+y=0$ (ii) $y=2x$ (iii) $y=2x+4$ (iv) $y=x-4$
$(c)$ For Fig. (iii),
$(i)$ $x+y=0$ (ii) $y=2x$ (iii) $y=2x+1$ (iv) $y=2x-4$

Draw the graph of $x + y = 7$.