Answer:
The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept. I'll be using question a to explain how to find the equation of a straight line graph.
To find the equation of a line, you would need:
① Gradient
② A coordinate
Let's identify the two coordinates given first.
They are (0,3) and (-3,0)
To find the gradient, use the formula below.
[tex]gradient = \frac{y1 - y2}{x1 - x2} [/tex]
Thus, gradient of line
[tex] = \frac{3 - 0}{0 - ( - 3)} \\ = \frac{3}{3} \\ = 1[/tex]
Subst. m=1 into the equation:
y= x +c
If the y-intercept is not given, you can substitute a coordinate into the equation to find the value of c.
However, it is already given for this question and you can see that the y-intercept occurs at y=3. Thus, c=3.
Hence, the equation of the line is y= x +3.
