How do you find the difference #2-9#?

1 Answer
Jan 27, 2017

Just another way of thinking about it

#-7#

Explanation:

Given: #color(red)(color(green)(2)-9)#

9 can be split into #2+7#

But we have -9 so this can be split as #-2-7#

So write #" "color(red)(color(green)(2)-9)" as "color(red)(color(green)(2)-2-7)#

#color(white)(.)#

but #color(green)(2)color(red)(-2) = 0# giving

#color(white)(.)#

#0-7#

So the answer is #-7#