The line can be expressed in slope intercept form in the following manner:
[tex]y(x)\text{ = m}\cdot x\text{ + b}[/tex]Where "m" is the slope and "b" is the y-intercept. We need at least two known points to find the expression. The expression of the slope is given by:
[tex]m\text{ = }\frac{y_2-y_1}{x_2-x_1}[/tex]Applying the known points (0.1, -1.6) and (3, 7.7).
[tex]\begin{gathered} m\text{ = }\frac{7.7\text{ - (-1.6)}}{3\text{ - 0.1}} \\ m\text{ = }\frac{7.7\text{ + 1.6}}{2.9} \\ m\text{ = }\frac{9.3}{2.9} \\ m\text{ = }3.21 \end{gathered}[/tex]The expression of the line thus far is:
[tex]y(x)\text{ = 3.21}\cdot x\text{ + b}[/tex]We need to find the value of "b", to do that we need to apply one of the known points:
[tex]\begin{gathered} -1.6=3.21\cdot0.1+b \\ -1.6=0.321+b \\ b=-1.6-0.321 \\ b=-1.921 \end{gathered}[/tex]We now have the whole expression of the line:
[tex]y(x)=3.21\cdot x-1.921[/tex]