Answer the following True or False:

If $\displaystyle {h}{\left({x},{y}\right)}$ is differentiable, then the slope of the tangent line to $\displaystyle {h}{\left({x},{y}\right)}={1}$ at $\displaystyle {x}={1}$ is equal to the slope of the tangent line to $\displaystyle {h}{\left({x},{y}\right)}={2}$ at $\displaystyle {x}={1}.$