$(\,a+\,1)\;(\,2\,b+\,4) = $   ?

$\,8\,\,a^2\,b^2 +\,4$ $\,3\,\,a\,b +\,5\,\,a +\,3\,\,b +\,5$ $\,2\,\,a\,b +\,4\,\,a +\,2\,\,b +\,4$ $\,2\,\,a\,b +\,4$

$(\,2+\,5\,a)\;(\,4+\,a) = $   ?

$\,5\,\,a^2 +\,22\,\,a +\,8$ $\,6\,\,a^2 +\,12\,\,a +\,6$ $\,27\,\,a +\,8$ $\,5\,\,a^2 +\,8$

$(\,3\,b+\,5)\;(\,2+\,4\,a) = $   ?

$\,12\,\,a\,b +\,10$ $\,38\,\,a^2\,b^2 +\,10$ $\,5\,\,b +\,7\,\,a\,b +\,7 +\,9\,\,a$ $\,6\,\,b +\,12\,\,a\,b +\,10 +\,20\,\,a$

$(\,6\,x+\,1)\;(\,4+\,5\,x) = $   ?

$\,59\,\,x +\,4$ $\,11\,\,x^2 +\,16\,\,x +\,5$ $\,30\,\,x^2 +\,4$ $\,30\,\,x^2 +\,29\,\,x +\,4$

$(\,6+\,t)\;(\,5\,-4\,x) = $   ?

$\,30 \,-24\,\,x +\,5\,\,t \,-4\,\,t\,x$ $\,30 +\,24\,\,x +\,5\,\,t +\,4\,\,t\,x$ $\,30 \,-24\,\,x +\,5\,\,t +\,4\,\,t\,x$ $\,-30 \,-24\,\,x +\,5\,\,t +\,4\,\,t\,x$

$(\,x+\,5)\;(\,-\,y\,-2) = $   ?

$\,-\,\,x\,y +\,2\,\,x +\,5\,\,y \,-10$ $\,\,x\,y +\,2\,\,x \,-5\,\,y \,-10$ $\,-\,\,x\,y \,-2\,\,x \,-5\,\,y \,-10$ $\,\,x\,y \,-2\,\,x \,-5\,\,y +\,10$

$(\,3\,y+\,1)\;(\,y\,-5) = $   ?

$\,3\,\,y^2 \,-16\,\,y +\,5$ $\,3\,\,y^2 +\,16\,\,y \,-5$ $\,3\,\,y^2 +\,16\,\,y +\,5$ $\,3\,\,y^2 \,-14\,\,y \,-5$

$(\,2\,a\,-1)\;(\,-6\,-3\,b) = $   ?

$\,-12\,\,a \,-6\,\,a\,b \,-6 \,-3\,\,b$ $\,12\,\,a \,-6\,\,a\,b +\,6 +\,3\,\,b$ $\,-12\,\,a \,-6\,\,a\,b +\,6 +\,3\,\,b$ $\,-12\,\,a \,-6\,\,a\,b \,-6 +\,3\,\,b$

$(\,6\,x+\,1)\;(\,-5\,x\,-4) = $   ?

$\,-30\,\,x^2 \,-19\,\,x \,-4$ $\,-30\,\,x^2 +\,19\,\,x +\,4$ $\,30\,\,x^2 \,-29\,\,x +\,4$ $\,-30\,\,x^2 \,-29\,\,x \,-4$

$(\,1\,-4\,b)\;(\,-5\,b\,-3) = $   ?

$\,20\,\,b^2 +\,7\,\,b \,-3$ $\,20\,\,b^2 \,-17\,\,b \,-3$ $\,-20\,\,b^2 +\,17\,\,b \,-3$ $\,-20\,\,b^2 +\,7\,\,b \,-3$