$(\,2\,b+\,5)\;(\,1+\,3\,a) = $   ?

$\,23\,\,a^2\,b^2 +\,5$ $\,2\,\,b +\,6\,\,a\,b +\,5 +\,15\,\,a$ $\,3\,\,b +\,5\,\,a\,b +\,6 +\,8\,\,a$ $\,6\,\,a\,b +\,5$

$(\,5+\,t)\;(\,2+\,t) = $   ?

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

$(\,y+\,3)\;(\,4+\,x) = $   ?

$\,5\,\,y +\,2\,\,x\,y +\,7 +\,4\,\,x$ $\,\,x\,y +\,12$ $\,8\,\,x^2\,y^2 +\,12$ $\,4\,\,y +\,\,x\,y +\,12 +\,3\,\,x$

$(\,1+\,3\,y)\;(\,3\,y+\,5) = $   ?

$\,6\,\,y^2 +\,12\,\,y +\,6$ $\,9\,\,y^2 +\,18\,\,y +\,5$ $\,27\,\,y +\,5$ $\,9\,\,y^2 +\,5$

$(\,2+\,4\,t)\;(\,-5+\,2\,x) = $   ?

$\,-10 +\,4\,\,x \,-20\,\,t +\,8\,\,t\,x$ $\,10 \,-4\,\,x \,-20\,\,t +\,8\,\,t\,x$ $\,-10 \,-4\,\,x +\,20\,\,t +\,8\,\,t\,x$ $\,10 +\,4\,\,x \,-20\,\,t +\,8\,\,t\,x$

$(\,5\,b\,-2)\;(\,-4\,a+\,1) = $   ?

$\,-20\,\,a\,b +\,5\,\,b \,-8\,\,a \,-2$ $\,-20\,\,a\,b \,-5\,\,b \,-8\,\,a \,-2$ $\,-20\,\,a\,b +\,5\,\,b +\,8\,\,a \,-2$ $\,20\,\,a\,b +\,5\,\,b \,-8\,\,a \,-2$

$(\,4+\,2\,y)\;(\,-1+\,6\,y) = $   ?

$\,12\,\,y^2 \,-26\,\,y +\,4$ $\,-12\,\,y^2 +\,22\,\,y \,-4$ $\,12\,\,y^2 +\,22\,\,y \,-4$ $\,12\,\,y^2 \,-22\,\,y \,-4$

$(\,2\,-\,a)\;(\,-3\,-\,b) = $   ?

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

$(\,5+\,a)\;(\,-6\,a\,-2) = $   ?

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

$(\,6\,-6\,a)\;(\,-2\,-5\,a) = $   ?

$\,-30\,\,a^2 +\,42\,\,a \,-12$ $\,30\,\,a^2 \,-18\,\,a \,-12$ $\,30\,\,a^2 +\,42\,\,a +\,12$ $\,-30\,\,a^2 \,-18\,\,a +\,12$