Question

The graph below shows the relationship between number of people and profits earned (in $).


The equation of the above graph is .

• A. $y=3-2x$
• B. $y=2+3x$
• C. $y=3+2x$
• D. $y=2-3x$

Answer 1

The correct option is C $y=3+2x$

Equation of the graph with y-intercept of value $b$ is $y=mx+b$.


From the graph,
The red line cuts the y-axis at the point (0,3).
∴ y-intercept = (0,3)
$\Rightarrow \text{b}=3$

Consider any two points (1,5) and (2,7) on the line.

We know,
$\text{Slope (}m\text{)}=\frac{\text{Change in y-axis}}{\text{Change in x-axis}}=\frac{y_2-y_1}{x_2-x_1}$

∴ Slope of the line ($m$) $=\frac{y_2-y_1}{x_2-x_1}$ $=\frac{7-5}{2-1}$
$=2$

Putting the values of $m$ and $b$ in the point-slope equation form, we get,
Equation of the graph is $y=2x+3$.