Question

lign="absmiddle" class="latex-formula">

Answer 1

Remark

There are occasions where this is very handy to know. Use FOIL.

Solve

F: (First): x*y = xy

O: (Outside): x *(-9) = - 9x

I:(Inside): (-7)*y = - 7y

L:(Last): (-7)*(-9) = 63

Add the terms together

xy - 9x - 7y + 63   <<<< Answer