Question

x + y = 16
7x -20 y = 45​

Answer 1

{x+y=16 ×(20)

{7x–20y=4

{20x+20y=320

+{7x-20y=4

$27x = 324 \\ x = \frac{324}{27} \\ x = 12$

$x + y = 16 \\ y = 16 - x \\ y = 16 - 12 \\ y = 4$

S={12,4}