Correct. Substitute the coordinates of the point $\displaystyle{\left({1},-{2}\right)}\usepackage{cmbright}\Huge\$ for x and y in $\displaystyle{y}=-{3}{x}+{b}\usepackage{cmbright}\Huge\$ : $\displaystyle-{2}=-{3}{\left({1}\right)}+{b}\usepackage{cmbright}\Huge\$

Solve for b: $\displaystyle-{2}=-{3}+{b}\usepackage{cmbright}\Huge\$ , so $\displaystyle{1}={b}\usepackage{cmbright}\Huge\$

The y-intercept, b, of the line is 1.