$(\,6\,a+\,4)\;(\,3+\,b) = $   ?

$\,28\,\,a^2\,b^2 +\,12$ $\,18\,\,a +\,6\,\,a\,b +\,12 +\,4\,\,b$ $\,6\,\,a\,b +\,12$ $\,9\,\,a +\,7\,\,a\,b +\,7 +\,5\,\,b$

$(\,4+\,y)\;(\,1+\,2\,y) = $   ?

$\,2\,\,y^2 +\,9\,\,y +\,4$ $\,11\,\,y +\,4$ $\,2\,\,y^2 +\,4$ $\,3\,\,y^2 +\,8\,\,y +\,5$

$(\,4+\,5\,b)\;(\,a+\,4) = $   ?

$\,4\,\,a +\,16 +\,5\,\,a\,b +\,20\,\,b$ $\,5\,\,a +\,8 +\,6\,\,a\,b +\,9\,\,b$ $\,29\,\,a^2\,b^2 +\,16$ $\,5\,\,a\,b +\,16$

$(\,2+\,b)\;(\,b+\,2) = $   ?

$\,2\,\,b^2 +\,6\,\,b +\,4$ $\,5\,\,b +\,4$ $\,\,b^2 +\,4$ $\,\,b^2 +\,4\,\,b +\,4$

$(\,5\,x+\,3)\;(\,2\,-4\,y) = $   ?

$\,-10\,\,x +\,20\,\,x\,y +\,6 \,-12\,\,y$ $\,10\,\,x +\,20\,\,x\,y +\,6 \,-12\,\,y$ $\,10\,\,x \,-20\,\,x\,y \,-6 \,-12\,\,y$ $\,10\,\,x \,-20\,\,x\,y +\,6 \,-12\,\,y$

$(\,5\,-4\,y)\;(\,-3+\,x) = $   ?

$\,15 +\,5\,\,x +\,12\,\,y \,-4\,\,x\,y$ $\,-15 +\,5\,\,x +\,12\,\,y \,-4\,\,x\,y$ $\,-15 +\,5\,\,x \,-12\,\,y +\,4\,\,x\,y$ $\,15 \,-5\,\,x +\,12\,\,y \,-4\,\,x\,y$

$(\,5\,-\,a)\;(\,6\,a+\,1) = $   ?

$\,6\,\,a^2 +\,31\,\,a +\,5$ $\,-6\,\,a^2 \,-29\,\,a +\,5$ $\,-6\,\,a^2 +\,31\,\,a +\,5$ $\,-6\,\,a^2 +\,29\,\,a +\,5$

$(\,3\,-\,a)\;(\,-\,b\,-6) = $   ?

$\,-3\,\,b +\,18 +\,\,a\,b +\,6\,\,a$ $\,3\,\,b +\,18 +\,\,a\,b +\,6\,\,a$ $\,-3\,\,b \,-18 \,-\,\,a\,b +\,6\,\,a$ $\,-3\,\,b \,-18 +\,\,a\,b +\,6\,\,a$

$(\,x\,-4)\;(\,-\,x+\,5) = $   ?

$\,-\,\,x^2 +\,9\,\,x \,-20$ $\,-\,\,x^2 \,-\,\,x \,-20$ $\,\,x^2 +\,9\,\,x +\,20$ $\,\,x^2 +\,\,x \,-20$

$(\,5\,b\,-2)\;(\,-1\,-\,b) = $   ?

$\,-5\,\,b^2 \,-3\,\,b +\,2$ $\,5\,\,b^2 +\,7\,\,b +\,2$ $\,-5\,\,b^2 \,-3\,\,b \,-2$ $\,-5\,\,b^2 \,-7\,\,b +\,2$