Question

Y * x = 20 y + x = 9 what numbers are y and x equal to?

Answer 1

$y = 9 - x$
Substitute into
$y \times x = 20 \\ (9 - x) \times x = 20 \\ { - x}^{2} + 9x = 20 \\ {x}^{2} - 9x + 20 = 0 \\ (x - 5)(x -4) = 0 \\ x = 5 \: or \: x = 4$
When x = 5,
$y = 9 - 5 \\ y = 4$
When x = 4,
$y = 9 - 4 \\ y = 5$

x = 5, y = 4
x = 4, y = 5

Hope this helps. - M