ANSWER
The required equation is
[tex]y = 7 x+ 1[/tex]
EXPLANATION
Let the equation of the line be
[tex]y = mx + b...(1)[/tex]
where
[tex]m = 7[/tex]
is the slope of the line. We substitute this value of the slope into the equation (1) to obtain,
[tex]y = 7x + b...(2)[/tex]
Since the point (1,8) lies on the line, it must satisfy this equation.
We substitute the x and y value of the point into the equation(2) to get,
[tex] 8 = 7(1) + b[/tex]
This simplifies to give us,
[tex]8=7+b [/tex]
We solve for b to get,
[tex]b = 8 - 7[/tex]
[tex]b = 1[/tex]
We substitute the value of b back into equation (2) to get
[tex]y = 7x + 1[/tex]