$(\,2+\,2\,a)\;(\,5\,b+\,1) = $   ?

$\,7\,\,b +\,3 +\,7\,\,a\,b +\,3\,\,a$ $\,10\,\,b +\,2 +\,10\,\,a\,b +\,2\,\,a$ $\,22\,\,a^2\,b^2 +\,2$ $\,10\,\,a\,b +\,2$

$(\,x+\,4)\;(\,3+\,6\,x) = $   ?

$\,33\,\,x +\,12$ $\,6\,\,x^2 +\,12$ $\,6\,\,x^2 +\,27\,\,x +\,12$ $\,7\,\,x^2 +\,14\,\,x +\,7$

$(\,2\,b+\,4)\;(\,6+\,5\,a) = $   ?

$\,42\,\,a^2\,b^2 +\,24$ $\,10\,\,a\,b +\,24$ $\,12\,\,b +\,10\,\,a\,b +\,24 +\,20\,\,a$ $\,8\,\,b +\,7\,\,a\,b +\,10 +\,9\,\,a$

$(\,6+\,3\,t)\;(\,2\,t+\,5) = $   ?

$\,33\,\,t +\,30$ $\,6\,\,t^2 +\,30$ $\,5\,\,t^2 +\,16\,\,t +\,11$ $\,6\,\,t^2 +\,27\,\,t +\,30$

$(\,t+\,3)\;(\,-2\,x+\,5) = $   ?

$\,-2\,\,t\,x +\,5\,\,t \,-6\,\,x +\,15$ $\,-2\,\,t\,x +\,5\,\,t +\,6\,\,x \,-15$ $\,2\,\,t\,x \,-5\,\,t \,-6\,\,x +\,15$ $\,2\,\,t\,x +\,5\,\,t \,-6\,\,x +\,15$

$(\,1\,-\,y)\;(\,-\,x+\,5) = $   ?

$\,-\,\,x +\,5 +\,\,x\,y +\,5\,\,y$ $\,-\,\,x +\,5 +\,\,x\,y \,-5\,\,y$ $\,-\,\,x +\,5 \,-\,\,x\,y \,-5\,\,y$ $\,\,x \,-5 +\,\,x\,y \,-5\,\,y$

$(\,3+\,4\,y)\;(\,-\,y+\,3) = $   ?

$\,-4\,\,y^2 +\,9\,\,y +\,9$ $\,-4\,\,y^2 \,-15\,\,y +\,9$ $\,4\,\,y^2 +\,9\,\,y +\,9$ $\,-4\,\,y^2 +\,9\,\,y \,-9$

$(\,4\,-4\,a)\;(\,-6\,-\,b) = $   ?

$\,-24 \,-4\,\,b +\,24\,\,a +\,4\,\,a\,b$ $\,24 \,-4\,\,b +\,24\,\,a \,-4\,\,a\,b$ $\,-24 \,-4\,\,b +\,24\,\,a \,-4\,\,a\,b$ $\,24 \,-4\,\,b +\,24\,\,a +\,4\,\,a\,b$

$(\,6\,-\,t)\;(\,-2+\,6\,t) = $   ?

$\,6\,\,t^2 +\,38\,\,t \,-12$ $\,-6\,\,t^2 \,-34\,\,t +\,12$ $\,6\,\,t^2 \,-34\,\,t \,-12$ $\,-6\,\,t^2 +\,38\,\,t \,-12$

$(\,6\,t\,-4)\;(\,-5\,t\,-6) = $   ?

$\,30\,\,t^2 \,-16\,\,t +\,24$ $\,-30\,\,t^2 \,-56\,\,t \,-24$ $\,-30\,\,t^2 \,-16\,\,t \,-24$ $\,-30\,\,t^2 \,-16\,\,t +\,24$