Question

Observe the graph given below.
The equation of the line representing the relationship between Time spent and Payment is represented by ______.

• A. $y=8x+0.6$
• B. $y=6x+0.8$
• C. $y=0.8x+6$
• D. $y=0.6x+8$

Answer 1

The correct option is D $y=0.6x+8$

From the graph, you can see that when,
$x=0⟹y=8$
So, Initial value = y-intercept (c) = 8

Consider the points (2, 9.2) & (4, 10.4) on the graph.

You know,
$\text{Slope (m) = Rate of change =}\frac{Changeiny}{Changeinx}$

Putting values, you get:
$\text{Slope}\left(m\right)=\frac{10.4-9.2}{4-2}$
$=\frac{1.2}{2}$
$=\$0.6$/hour

$\text{We know, the general form of equation of a}$
$\text{straight line is given by:}y=mx+c$


Putting the value of "m" and "c" there, you get:
$y=0.6x+8$