For this case we have that by definition, the equation of a line in the slope-intersection form is given by:
![y = mx + b](https://img.qammunity.org/2020/formulas/mathematics/high-school/fc4cgm6covys37zv2opmmp9ps4jxyjepvh.png)
Where:
m: It's the slope
b: It is the cut-off point with the y axis
According to the data we have to:
![m = 3\\(x, y) :( 1,3)](https://img.qammunity.org/2020/formulas/mathematics/high-school/apgj0q29y053rlbaydudt4xb3yzyvipeac.png)
So, the equation is of the form:
![y = 3x + b](https://img.qammunity.org/2020/formulas/mathematics/high-school/guruavnyacrogfbtqpqgza41ja773sbtub.png)
We substitute the point and find b:
![3 = 3 (1) + b\\3 = 3 + b\\b = 3-3\\b = 0](https://img.qammunity.org/2020/formulas/mathematics/high-school/d1w30s0uppwpr6tngtoehb3mdq1wxm2drh.png)
Finally, the equation is of the form:
![y = 3x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jv2gjug2izxlhbs7zwdsuz8p1t0js9xbxd.png)
Answer:
![y = 3x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jv2gjug2izxlhbs7zwdsuz8p1t0js9xbxd.png)