Part a
For this case we have two points given (1,3) and (4,6) and we want to find the equation for this line and we can use this equation:
![y=mx+b](https://img.qammunity.org/2023/formulas/mathematics/high-school/smsb8cbft03lwblmi49nf2l6jby2ofxzws.png)
Where m represent the slope and b the intercept. We can estimate the slope with this formula:
![m=(y_2-y_1)/(x_2-x_1)=(6-3)/(4-1)=1](https://img.qammunity.org/2023/formulas/mathematics/college/mtrld9svj4ba9cpzccehzdjgf2ptiz3lee.png)
And then we can find the intercept from one point given and replacing into the equation like this:
![3=1\cdot1+b\rightarrow b=2](https://img.qammunity.org/2023/formulas/mathematics/college/wtaz6y5r8xpufhrpbrkpk9glt561fdzwne.png)
And the equation would be:
![y=x+2](https://img.qammunity.org/2023/formulas/mathematics/college/if5c6h3255s0fgswn15qlzqmvpgrrm8v0o.png)
Part b
Now we just need to see if the point (1,3) is on the line calculated let's check this. If x=1 we have that:
![y=1\cdot1+2=3](https://img.qammunity.org/2023/formulas/mathematics/college/7pa1sxhk1nprguradi6xsknvqvwj9zdd8z.png)
So then we verify that the point is on the line and then that would be the proof for this case.