Incorrect. Substitute the slope $\displaystyle-{4}\usepackage{cmbright}\Huge\$ into the equation $\displaystyle{y}={m}{x}+{b}\usepackage{cmbright}\Huge\$ : $\displaystyle{y}=-{4}{x}+{b}\usepackage{cmbright}\Huge\$

Substitute the coordinates of the point $\displaystyle{\left(-{3},{15}\right)}\usepackage{cmbright}\Huge\$ for x and y and solve for b to find the y-intercept.

The correct answer is 3.