$(\,3+\,5\,y)\;(\,2\,x+\,1) = $   ?

$\,21\,\,x^2\,y^2 +\,3$ $\,5\,\,x +\,4 +\,7\,\,x\,y +\,6\,\,y$ $\,6\,\,x +\,3 +\,10\,\,x\,y +\,5\,\,y$ $\,10\,\,x\,y +\,3$

$(\,t+\,6)\;(\,1+\,t) = $   ?

$\,\,t^2 +\,7\,\,t +\,6$ $\,8\,\,t +\,6$ $\,\,t^2 +\,6$ $\,2\,\,t^2 +\,9\,\,t +\,7$

$(\,x+\,3)\;(\,y+\,5) = $   ?

$\,2\,\,x\,y +\,6\,\,x +\,4\,\,y +\,8$ $\,\,x\,y +\,15$ $\,\,x\,y +\,5\,\,x +\,3\,\,y +\,15$ $\,9\,\,x^2\,y^2 +\,15$

$(\,2+\,y)\;(\,5+\,3\,y) = $   ?

$\,3\,\,y^2 +\,10$ $\,4\,\,y^2 +\,11\,\,y +\,7$ $\,14\,\,y +\,10$ $\,3\,\,y^2 +\,11\,\,y +\,10$

$(\,5\,y+\,3)\;(\,2\,-6\,x) = $   ?

$\,-10\,\,y \,-30\,\,x\,y +\,6 +\,18\,\,x$ $\,-10\,\,y \,-30\,\,x\,y \,-6 \,-18\,\,x$ $\,10\,\,y \,-30\,\,x\,y +\,6 \,-18\,\,x$ $\,10\,\,y +\,30\,\,x\,y +\,6 +\,18\,\,x$

$(\,1\,-\,b)\;(\,-5+\,2\,a) = $   ?

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

$(\,2\,y+\,2)\;(\,y\,-1) = $   ?

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

$(\,3\,y\,-3)\;(\,-1\,-5\,x) = $   ?

$\,-3\,\,y \,-15\,\,x\,y +\,3 \,-15\,\,x$ $\,-3\,\,y \,-15\,\,x\,y +\,3 +\,15\,\,x$ $\,-3\,\,y \,-15\,\,x\,y \,-3 \,-15\,\,x$ $\,3\,\,y +\,15\,\,x\,y +\,3 +\,15\,\,x$

$(\,5\,t\,-3)\;(\,-4+\,2\,t) = $   ?

$\,10\,\,t^2 +\,26\,\,t +\,12$ $\,-10\,\,t^2 +\,14\,\,t +\,12$ $\,10\,\,t^2 \,-26\,\,t +\,12$ $\,10\,\,t^2 \,-26\,\,t \,-12$

$(\,6\,t\,-2)\;(\,-5\,-\,t) = $   ?

$\,6\,\,t^2 \,-28\,\,t +\,10$ $\,-6\,\,t^2 \,-32\,\,t +\,10$ $\,6\,\,t^2 \,-32\,\,t +\,10$ $\,-6\,\,t^2 \,-28\,\,t +\,10$