Question 670482
If you have variables, like {{{ a }}}, {{{ b }}}, and {{{ c }}}
For multiplication:
{{{ (+a)*(+b) = +(a*b) }}}
{{{ (-a)*(-b) = +(a*b) }}}
{{{ (+a)*(-b) = -(a*b) }}}
{{{ (-a)*(+b) = -(a*b) }}}
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For addition with parentheses:
{{{ a + ( b + c ) = a + b + c }}}
{{{ a + ( b - c ) = a + b - c }}}
{{{ a - ( b + c ) = a - b - c }}}
{{{ a - ( b - c ) = a -b + c }}}
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Hope this helps