Question

Graph y = 2/5x - 1. Is the point (10, 4) on the line?

Answer 1

Given the equation

$y=\frac{2}{5}x-1$

Set (x,y)=(10,4); thus,

$\begin{gathered} \mleft(x,y\mright)=\mleft(10,4\mright) \\ \Rightarrow4=\frac{2}{5}(10)-1 \\ \Rightarrow4=2\cdot2-1 \\ \Rightarrow4=4-1 \\ \Rightarrow4=3!!! \end{gathered}$

4=3 is impossible; therefore, (10,4) is not on the line