Subtract 
x-y
is equivalent to x+(-1*y).
Examples
open allclose allScope (3)
Wolfram Research (1988), Subtract, Wolfram Language function, https://reference.wolfram.com/language/ref/Subtract.html.
Text
Wolfram Research (1988), Subtract, Wolfram Language function, https://reference.wolfram.com/language/ref/Subtract.html.
CMS
Wolfram Language. 1988. "Subtract." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Subtract.html.
APA
Wolfram Language. (1988). Subtract. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Subtract.html