$(\,3+\,3\,y)\;(\,x+\,4) = $   ?

$\,4\,\,x +\,7 +\,4\,\,x\,y +\,7\,\,y$ $\,18\,\,x^2\,y^2 +\,12$ $\,3\,\,x +\,12 +\,3\,\,x\,y +\,12\,\,y$ $\,3\,\,x\,y +\,12$

$(\,2\,y+\,6)\;(\,4\,y+\,5) = $   ?

$\,6\,\,y^2 +\,17\,\,y +\,11$ $\,8\,\,y^2 +\,30$ $\,8\,\,y^2 +\,34\,\,y +\,30$ $\,42\,\,y +\,30$

$(\,3+\,2\,b)\;(\,4+\,a) = $   ?

$\,13\,\,a^2\,b^2 +\,12$ $\,2\,\,a\,b +\,12$ $\,7 +\,4\,\,a +\,6\,\,b +\,3\,\,a\,b$ $\,12 +\,3\,\,a +\,8\,\,b +\,2\,\,a\,b$

$(\,6+\,y)\;(\,5+\,y) = $   ?

$\,\,y^2 +\,11\,\,y +\,30$ $\,\,y^2 +\,30$ $\,2\,\,y^2 +\,13\,\,y +\,11$ $\,12\,\,y +\,30$

$(\,5\,a\,-2)\;(\,4+\,6\,b) = $   ?

$\,-20\,\,a +\,30\,\,a\,b \,-8 +\,12\,\,b$ $\,20\,\,a +\,30\,\,a\,b +\,8 +\,12\,\,b$ $\,20\,\,a +\,30\,\,a\,b \,-8 \,-12\,\,b$ $\,-20\,\,a +\,30\,\,a\,b \,-8 \,-12\,\,b$

$(\,4\,a+\,2)\;(\,-2\,b\,-3) = $   ?

$\,8\,\,a\,b \,-12\,\,a \,-4\,\,b \,-6$ $\,-8\,\,a\,b \,-12\,\,a +\,4\,\,b \,-6$ $\,-8\,\,a\,b +\,12\,\,a +\,4\,\,b \,-6$ $\,-8\,\,a\,b \,-12\,\,a \,-4\,\,b \,-6$

$(\,6\,y+\,1)\;(\,-\,y+\,3) = $   ?

$\,6\,\,y^2 +\,19\,\,y +\,3$ $\,6\,\,y^2 +\,17\,\,y +\,3$ $\,-6\,\,y^2 +\,17\,\,y \,-3$ $\,-6\,\,y^2 +\,17\,\,y +\,3$

$(\,a\,-2)\;(\,-3\,b\,-4) = $   ?

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

$(\,6\,a\,-1)\;(\,2\,-6\,a) = $   ?

$\,-36\,\,a^2 +\,6\,\,a +\,2$ $\,36\,\,a^2 \,-6\,\,a \,-2$ $\,-36\,\,a^2 \,-6\,\,a +\,2$ $\,-36\,\,a^2 +\,18\,\,a \,-2$

$(\,4\,-6\,t)\;(\,-2\,t\,-4) = $   ?

$\,-12\,\,t^2 \,-32\,\,t \,-16$ $\,12\,\,t^2 +\,16\,\,t \,-16$ $\,12\,\,t^2 +\,32\,\,t \,-16$ $\,12\,\,t^2 +\,32\,\,t +\,16$