Question

check weather the points (1,5), (0,3) lie on the line y =3 +2x or not

Answer 1

A point (h,k) lies on a straight $ax+by+c=0$ iff $ah+bk+c=0.$
Now, point (1,5) lies on line $$\begin{gathered} y=3+2xiff \\ 5=3+2\left(1\right)=5 \\ whichistrue,so\left(1,5\right)liesontheliney=3+2x \end{gathered}$$
$$\begin{gathered} similarly,point\left(0,3\right)liesontheliney=3+2xiff \\ 3=3+2\left(0\right)=3 \\ whichistrue,sopoint\left(0,3\right)liesontheline. \end{gathered}$$