Draw the graph and mark the function value $f(-1)f\backslash left(-1\backslash right)$ .

Check whether the point $P(\sqrt{7}\mathrm{\mid }-1.54)P(\backslash sqrt\; 7\; \backslash ,\; |\; -\; 1.54)$ lies on the graph of the function.

To do this, insert the $xx$-value $\sqrt{7}\backslash sqrt7$ into the function equation $y(x)=3-\frac{12}{7}xy(x)\; =\; 3\; -\; \backslash frac\{12\}\{7\}x$.

Result

The point $P(\sqrt{7}\mathrm{\mid }-1.54)P(\backslash sqrt\; 7\; \backslash ,\; |\; -\; 1.54)$ is not on the graph because the function value of $\sqrt{7}\backslash sqrt\{7\}$ is a non-terminating decimal fraction and not the finite decimal fraction $-1.54-1.54$.

If you have calculated with rounded values, you might have mistakenly conclude that the point is on the graph. However, this is not the case.