$(\,t+\,2)\;(\,x+\,4) = $   ?

$\,2\,\,t\,x +\,5\,\,t +\,3\,\,x +\,6$ $\,7\,\,t^2\,x^2 +\,8$ $\,\,t\,x +\,4\,\,t +\,2\,\,x +\,8$ $\,\,t\,x +\,8$

$(\,4\,t+\,6)\;(\,3\,t+\,4) = $   ?

$\,12\,\,t^2 +\,34\,\,t +\,24$ $\,46\,\,t +\,24$ $\,7\,\,t^2 +\,17\,\,t +\,10$ $\,12\,\,t^2 +\,24$

$(\,3+\,2\,x)\;(\,2+\,3\,y) = $   ?

$\,6 +\,9\,\,y +\,4\,\,x +\,6\,\,x\,y$ $\,6\,\,x\,y +\,6$ $\,5 +\,6\,\,y +\,4\,\,x +\,5\,\,x\,y$ $\,19\,\,x^2\,y^2 +\,6$

$(\,1+\,4\,t)\;(\,5+\,2\,t) = $   ?

$\,6\,\,t^2 +\,12\,\,t +\,6$ $\,30\,\,t +\,5$ $\,8\,\,t^2 +\,5$ $\,8\,\,t^2 +\,22\,\,t +\,5$

$(\,6+\,4\,t)\;(\,5\,x\,-1) = $   ?

$\,-30\,\,x +\,6 +\,20\,\,t\,x \,-4\,\,t$ $\,30\,\,x \,-6 +\,20\,\,t\,x \,-4\,\,t$ $\,-30\,\,x \,-6 \,-20\,\,t\,x \,-4\,\,t$ $\,30\,\,x +\,6 +\,20\,\,t\,x +\,4\,\,t$

$(\,5\,b\,-2)\;(\,6\,-\,a) = $   ?

$\,30\,\,b \,-5\,\,a\,b \,-12 \,-2\,\,a$ $\,30\,\,b \,-5\,\,a\,b \,-12 +\,2\,\,a$ $\,-30\,\,b \,-5\,\,a\,b +\,12 +\,2\,\,a$ $\,-30\,\,b \,-5\,\,a\,b \,-12 \,-2\,\,a$

$(\,6\,x+\,3)\;(\,2\,-\,x) = $   ?

$\,6\,\,x^2 +\,9\,\,x \,-6$ $\,-6\,\,x^2 \,-15\,\,x +\,6$ $\,-6\,\,x^2 \,-15\,\,x \,-6$ $\,-6\,\,x^2 +\,9\,\,x +\,6$

$(\,x\,-1)\;(\,-\,y\,-4) = $   ?

$\,-\,\,x\,y \,-4\,\,x +\,\,y +\,4$ $\,\,x\,y \,-4\,\,x +\,\,y +\,4$ $\,-\,\,x\,y +\,4\,\,x \,-\,\,y +\,4$ $\,\,x\,y \,-4\,\,x \,-\,\,y +\,4$

$(\,5\,-6\,a)\;(\,-4\,a+\,3) = $   ?

$\,-24\,\,a^2 +\,2\,\,a +\,15$ $\,24\,\,a^2 \,-38\,\,a +\,15$ $\,24\,\,a^2 \,-2\,\,a +\,15$ $\,24\,\,a^2 +\,2\,\,a \,-15$

$(\,y\,-3)\;(\,-\,y\,-4) = $   ?

$\,\,y^2 \,-\,\,y \,-12$ $\,-\,\,y^2 \,-\,\,y \,-12$ $\,-\,\,y^2 +\,7\,\,y \,-12$ $\,-\,\,y^2 \,-\,\,y +\,12$