$(\,x+\,1)\;(\,1+\,6\,y) = $   ?

$\,\,x +\,6\,\,x\,y +\,1 +\,6\,\,y$ $\,2\,\,x +\,7\,\,x\,y +\,2 +\,7\,\,y$ $\,13\,\,x^2\,y^2 +\,1$ $\,6\,\,x\,y +\,1$

$(\,1+\,y)\;(\,y+\,3) = $   ?

$\,5\,\,y +\,3$ $\,\,y^2 +\,4\,\,y +\,3$ $\,2\,\,y^2 +\,6\,\,y +\,4$ $\,\,y^2 +\,3$

$(\,5\,a+\,3)\;(\,3+\,5\,b) = $   ?

$\,25\,\,a\,b +\,9$ $\,55\,\,a^2\,b^2 +\,9$ $\,15\,\,a +\,25\,\,a\,b +\,9 +\,15\,\,b$ $\,8\,\,a +\,10\,\,a\,b +\,6 +\,8\,\,b$

$(\,2+\,4\,a)\;(\,4+\,a) = $   ?

$\,4\,\,a^2 +\,18\,\,a +\,8$ $\,22\,\,a +\,8$ $\,5\,\,a^2 +\,11\,\,a +\,6$ $\,4\,\,a^2 +\,8$

$(\,3\,b+\,2)\;(\,5\,-4\,a) = $   ?

$\,-15\,\,b \,-12\,\,a\,b +\,10 +\,8\,\,a$ $\,15\,\,b \,-12\,\,a\,b \,-10 +\,8\,\,a$ $\,-15\,\,b \,-12\,\,a\,b +\,10 \,-8\,\,a$ $\,15\,\,b \,-12\,\,a\,b +\,10 \,-8\,\,a$

$(\,2+\,b)\;(\,-3\,-2\,a) = $   ?

$\,-6 \,-4\,\,a +\,3\,\,b \,-2\,\,a\,b$ $\,-6 +\,4\,\,a \,-3\,\,b \,-2\,\,a\,b$ $\,-6 \,-4\,\,a \,-3\,\,b \,-2\,\,a\,b$ $\,6 \,-4\,\,a +\,3\,\,b \,-2\,\,a\,b$

$(\,3+\,t)\;(\,5\,-\,t) = $   ?

$\,-\,\,t^2 \,-8\,\,t +\,15$ $\,-\,\,t^2 +\,2\,\,t +\,15$ $\,-\,\,t^2 \,-8\,\,t \,-15$ $\,-\,\,t^2 +\,8\,\,t +\,15$

$(\,y\,-2)\;(\,-4\,-5\,x) = $   ?

$\,-4\,\,y +\,5\,\,x\,y +\,8 \,-10\,\,x$ $\,-4\,\,y \,-5\,\,x\,y +\,8 +\,10\,\,x$ $\,-4\,\,y +\,5\,\,x\,y +\,8 +\,10\,\,x$ $\,-4\,\,y \,-5\,\,x\,y \,-8 \,-10\,\,x$

$(\,4\,x\,-3)\;(\,-5\,x+\,1) = $   ?

$\,-20\,\,x^2 +\,11\,\,x +\,3$ $\,20\,\,x^2 +\,19\,\,x +\,3$ $\,-20\,\,x^2 +\,19\,\,x \,-3$ $\,-20\,\,x^2 \,-19\,\,x \,-3$

$(\,5\,-\,x)\;(\,-6\,-\,x) = $   ?

$\,\,x^2 +\,\,x \,-30$ $\,\,x^2 +\,11\,\,x +\,30$ $\,-\,\,x^2 +\,\,x \,-30$ $\,\,x^2 +\,\,x +\,30$