$(\,6+\,a)\;(\,3\,b+\,6) = $   ?

$\,9\,\,b +\,12 +\,4\,\,a\,b +\,7\,\,a$ $\,18\,\,b +\,36 +\,3\,\,a\,b +\,6\,\,a$ $\,27\,\,a^2\,b^2 +\,36$ $\,3\,\,a\,b +\,36$

$(\,5\,t+\,5)\;(\,3\,t+\,6) = $   ?

$\,60\,\,t +\,30$ $\,15\,\,t^2 +\,30$ $\,15\,\,t^2 +\,45\,\,t +\,30$ $\,8\,\,t^2 +\,19\,\,t +\,11$

$(\,4\,a+\,5)\;(\,5+\,4\,b) = $   ?

$\,56\,\,a^2\,b^2 +\,25$ $\,16\,\,a\,b +\,25$ $\,20\,\,a +\,16\,\,a\,b +\,25 +\,20\,\,b$ $\,9\,\,a +\,8\,\,a\,b +\,10 +\,9\,\,b$

$(\,3\,t+\,3)\;(\,t+\,6) = $   ?

$\,3\,\,t^2 +\,21\,\,t +\,18$ $\,24\,\,t +\,18$ $\,3\,\,t^2 +\,18$ $\,4\,\,t^2 +\,13\,\,t +\,9$

$(\,2+\,b)\;(\,4\,a\,-3) = $   ?

$\,-8\,\,a \,-6 \,-4\,\,a\,b \,-3\,\,b$ $\,8\,\,a \,-6 \,-4\,\,a\,b +\,3\,\,b$ $\,8\,\,a \,-6 +\,4\,\,a\,b \,-3\,\,b$ $\,-8\,\,a \,-6 +\,4\,\,a\,b \,-3\,\,b$

$(\,3+\,4\,x)\;(\,-2\,-\,y) = $   ?

$\,-6 \,-3\,\,y +\,8\,\,x +\,4\,\,x\,y$ $\,-6 \,-3\,\,y +\,8\,\,x \,-4\,\,x\,y$ $\,-6 \,-3\,\,y \,-8\,\,x \,-4\,\,x\,y$ $\,-6 \,-3\,\,y \,-8\,\,x +\,4\,\,x\,y$

$(\,y+\,6)\;(\,5\,y\,-1) = $   ?

$\,5\,\,y^2 \,-31\,\,y +\,6$ $\,5\,\,y^2 \,-31\,\,y \,-6$ $\,5\,\,y^2 +\,29\,\,y \,-6$ $\,-5\,\,y^2 \,-31\,\,y \,-6$

$(\,5\,-6\,a)\;(\,-4\,b\,-2) = $   ?

$\,20\,\,b \,-10 \,-24\,\,a\,b +\,12\,\,a$ $\,20\,\,b \,-10 +\,24\,\,a\,b +\,12\,\,a$ $\,-20\,\,b \,-10 +\,24\,\,a\,b +\,12\,\,a$ $\,20\,\,b +\,10 +\,24\,\,a\,b +\,12\,\,a$

$(\,4+\,4\,y)\;(\,-\,y\,-6) = $   ?

$\,-4\,\,y^2 +\,28\,\,y \,-24$ $\,4\,\,y^2 \,-28\,\,y \,-24$ $\,-4\,\,y^2 \,-28\,\,y +\,24$ $\,-4\,\,y^2 \,-28\,\,y \,-24$

$(\,4\,-6\,a)\;(\,-2\,-4\,a) = $   ?

$\,24\,\,a^2 \,-4\,\,a +\,8$ $\,24\,\,a^2 \,-4\,\,a \,-8$ $\,-24\,\,a^2 \,-4\,\,a \,-8$ $\,-24\,\,a^2 \,-28\,\,a \,-8$