$(\,5\,a+\,5)\;(\,1+\,3\,b) = $   ?

$\,5\,\,a +\,15\,\,a\,b +\,5 +\,15\,\,b$ $\,35\,\,a^2\,b^2 +\,5$ $\,6\,\,a +\,8\,\,a\,b +\,6 +\,8\,\,b$ $\,15\,\,a\,b +\,5$

$(\,1+\,a)\;(\,5+\,6\,a) = $   ?

$\,6\,\,a^2 +\,11\,\,a +\,5$ $\,17\,\,a +\,5$ $\,6\,\,a^2 +\,5$ $\,7\,\,a^2 +\,13\,\,a +\,6$

$(\,3\,y+\,5)\;(\,1+\,2\,x) = $   ?

$\,4\,\,y +\,5\,\,x\,y +\,6 +\,7\,\,x$ $\,19\,\,x^2\,y^2 +\,5$ $\,3\,\,y +\,6\,\,x\,y +\,5 +\,10\,\,x$ $\,6\,\,x\,y +\,5$

$(\,5+\,5\,t)\;(\,6+\,2\,t) = $   ?

$\,10\,\,t^2 +\,40\,\,t +\,30$ $\,50\,\,t +\,30$ $\,7\,\,t^2 +\,18\,\,t +\,11$ $\,10\,\,t^2 +\,30$

$(\,3+\,y)\;(\,2\,-6\,x) = $   ?

$\,6 \,-18\,\,x +\,2\,\,y \,-6\,\,x\,y$ $\,-6 +\,18\,\,x +\,2\,\,y \,-6\,\,x\,y$ $\,-6 \,-18\,\,x \,-2\,\,y \,-6\,\,x\,y$ $\,-6 \,-18\,\,x +\,2\,\,y +\,6\,\,x\,y$

$(\,1\,-4\,x)\;(\,6\,y\,-1) = $   ?

$\,6\,\,y +\,1 \,-24\,\,x\,y \,-4\,\,x$ $\,-6\,\,y +\,1 \,-24\,\,x\,y +\,4\,\,x$ $\,6\,\,y \,-1 \,-24\,\,x\,y +\,4\,\,x$ $\,6\,\,y +\,1 +\,24\,\,x\,y +\,4\,\,x$

$(\,a+\,1)\;(\,-\,a+\,4) = $   ?

$\,\,a^2 +\,3\,\,a +\,4$ $\,-\,\,a^2 +\,5\,\,a \,-4$ $\,-\,\,a^2 +\,3\,\,a +\,4$ $\,\,a^2 \,-5\,\,a +\,4$

$(\,4\,x\,-1)\;(\,-\,y\,-4) = $   ?

$\,4\,\,x\,y \,-16\,\,x \,-\,\,y +\,4$ $\,-4\,\,x\,y \,-16\,\,x \,-\,\,y +\,4$ $\,-4\,\,x\,y +\,16\,\,x +\,\,y \,-4$ $\,-4\,\,x\,y \,-16\,\,x +\,\,y +\,4$

$(\,4\,-5\,b)\;(\,b\,-3) = $   ?

$\,5\,\,b^2 +\,19\,\,b \,-12$ $\,-5\,\,b^2 +\,19\,\,b \,-12$ $\,-5\,\,b^2 +\,11\,\,b +\,12$ $\,-5\,\,b^2 \,-11\,\,b \,-12$

$(\,x\,-4)\;(\,-6\,x\,-5) = $   ?

$\,-6\,\,x^2 \,-29\,\,x \,-20$ $\,6\,\,x^2 \,-29\,\,x +\,20$ $\,-6\,\,x^2 +\,19\,\,x +\,20$ $\,-6\,\,x^2 \,-29\,\,x +\,20$