Answer:
y=x+4
Step-by-step explanation:
y=mx+c,
where m is the gradient and c is the y-intercept.
[tex]gradient = \frac{y1 - y2}{x1 - x2} [/tex]
Using the above formula,
[tex]slope \: of \: AB \\ = \frac{9 - 7}{5 - 3} \\ = \frac{2}{2} \\ = 1[/tex]
y=1x+c
since 1x is redundant, we simply write it as y=x+c.
To find the y-intercept, substitute a coordinate into the equation.
When x=3, y=7,
7= 3+c
c= 7-3 (-3 on both sides)
c= 4 (simplify)
Thus the equation of line AB is y= x+4.
