How do you find the x and y intercepts for 5x - 2y = 20?

Use $x = 0$ and $y = 0$ in turns
$x = 0 , y$-intercept
$5 \cdot 0 - 2 y = 20 \to y = - 10 \to \left(0 , - 10\right)$
$y = 0 , x$-intercept
$5 x - 2 \cdot 0 = 20 \to x = 4 \to \left(4 , 0\right)$