$(\,5+\,6\,y)\;(\,4\,x+\,5) = $   ?

$\,74\,\,x^2\,y^2 +\,25$ $\,24\,\,x\,y +\,25$ $\,9\,\,x +\,10 +\,10\,\,x\,y +\,11\,\,y$ $\,20\,\,x +\,25 +\,24\,\,x\,y +\,30\,\,y$

$(\,2+\,a)\;(\,5+\,a) = $   ?

$\,\,a^2 +\,7\,\,a +\,10$ $\,2\,\,a^2 +\,9\,\,a +\,7$ $\,\,a^2 +\,10$ $\,8\,\,a +\,10$

$(\,2\,b+\,3)\;(\,a+\,4) = $   ?

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

$(\,t+\,2)\;(\,4\,t+\,6) = $   ?

$\,4\,\,t^2 +\,12$ $\,4\,\,t^2 +\,14\,\,t +\,12$ $\,5\,\,t^2 +\,13\,\,t +\,8$ $\,18\,\,t +\,12$

$(\,3\,t\,-3)\;(\,x+\,1) = $   ?

$\,3\,\,t\,x +\,3\,\,t \,-3\,\,x \,-3$ $\,3\,\,t\,x +\,3\,\,t +\,3\,\,x +\,3$ $\,-3\,\,t\,x +\,3\,\,t \,-3\,\,x \,-3$ $\,-3\,\,t\,x +\,3\,\,t +\,3\,\,x \,-3$

$(\,3\,-\,a)\;(\,-5\,b+\,4) = $   ?

$\,-15\,\,b +\,12 +\,5\,\,a\,b +\,4\,\,a$ $\,-15\,\,b +\,12 \,-5\,\,a\,b +\,4\,\,a$ $\,15\,\,b +\,12 +\,5\,\,a\,b \,-4\,\,a$ $\,-15\,\,b +\,12 +\,5\,\,a\,b \,-4\,\,a$

$(\,3\,t+\,1)\;(\,-5+\,2\,t) = $   ?

$\,-6\,\,t^2 \,-13\,\,t \,-5$ $\,6\,\,t^2 \,-13\,\,t \,-5$ $\,-6\,\,t^2 +\,17\,\,t \,-5$ $\,6\,\,t^2 +\,17\,\,t +\,5$

$(\,6\,-4\,b)\;(\,-4\,a\,-6) = $   ?

$\,-24\,\,a +\,36 +\,16\,\,a\,b \,-24\,\,b$ $\,24\,\,a \,-36 +\,16\,\,a\,b \,-24\,\,b$ $\,-24\,\,a \,-36 +\,16\,\,a\,b +\,24\,\,b$ $\,24\,\,a +\,36 +\,16\,\,a\,b +\,24\,\,b$

$(\,3\,x\,-4)\;(\,6\,-\,x) = $   ?

$\,-3\,\,x^2 \,-14\,\,x \,-24$ $\,-3\,\,x^2 +\,22\,\,x \,-24$ $\,3\,\,x^2 +\,22\,\,x \,-24$ $\,-3\,\,x^2 \,-22\,\,x \,-24$

$(\,5\,x\,-4)\;(\,-\,x\,-6) = $   ?

$\,-5\,\,x^2 \,-26\,\,x +\,24$ $\,-5\,\,x^2 +\,34\,\,x +\,24$ $\,-5\,\,x^2 \,-26\,\,x \,-24$ $\,-5\,\,x^2 \,-34\,\,x +\,24$