$(\,5+\,4\,a)\;(\,3+\,6\,b) = $   ?

$\,24\,\,a\,b +\,15$ $\,15 +\,30\,\,b +\,12\,\,a +\,24\,\,a\,b$ $\,8 +\,11\,\,b +\,7\,\,a +\,10\,\,a\,b$ $\,66\,\,a^2\,b^2 +\,15$

$(\,4\,t+\,3)\;(\,1+\,t) = $   ?

$\,4\,\,t^2 +\,7\,\,t +\,3$ $\,11\,\,t +\,3$ $\,5\,\,t^2 +\,9\,\,t +\,4$ $\,4\,\,t^2 +\,3$

$(\,t+\,2)\;(\,2\,x+\,5) = $   ?

$\,2\,\,t\,x +\,10$ $\,3\,\,t\,x +\,6\,\,t +\,4\,\,x +\,7$ $\,2\,\,t\,x +\,5\,\,t +\,4\,\,x +\,10$ $\,11\,\,t^2\,x^2 +\,10$

$(\,4\,a+\,3)\;(\,6\,a+\,2) = $   ?

$\,24\,\,a^2 +\,6$ $\,10\,\,a^2 +\,15\,\,a +\,5$ $\,24\,\,a^2 +\,26\,\,a +\,6$ $\,50\,\,a +\,6$

$(\,b+\,4)\;(\,4\,-6\,a) = $   ?

$\,4\,\,b \,-6\,\,a\,b +\,16 \,-24\,\,a$ $\,4\,\,b \,-6\,\,a\,b \,-16 +\,24\,\,a$ $\,-4\,\,b \,-6\,\,a\,b +\,16 +\,24\,\,a$ $\,-4\,\,b \,-6\,\,a\,b +\,16 \,-24\,\,a$

$(\,4\,b\,-3)\;(\,-1+\,6\,a) = $   ?

$\,-4\,\,b +\,24\,\,a\,b +\,3 \,-18\,\,a$ $\,-4\,\,b +\,24\,\,a\,b \,-3 \,-18\,\,a$ $\,4\,\,b +\,24\,\,a\,b +\,3 \,-18\,\,a$ $\,-4\,\,b \,-24\,\,a\,b +\,3 \,-18\,\,a$

$(\,a+\,2)\;(\,2\,-5\,a) = $   ?

$\,5\,\,a^2 +\,12\,\,a +\,4$ $\,5\,\,a^2 \,-8\,\,a \,-4$ $\,-5\,\,a^2 \,-8\,\,a +\,4$ $\,5\,\,a^2 \,-8\,\,a +\,4$

$(\,4\,-\,x)\;(\,-6\,-3\,y) = $   ?

$\,24 +\,12\,\,y +\,6\,\,x +\,3\,\,x\,y$ $\,-24 \,-12\,\,y +\,6\,\,x +\,3\,\,x\,y$ $\,-24 +\,12\,\,y +\,6\,\,x \,-3\,\,x\,y$ $\,-24 +\,12\,\,y +\,6\,\,x +\,3\,\,x\,y$

$(\,5\,x+\,5)\;(\,-6\,-2\,x) = $   ?

$\,-10\,\,x^2 \,-40\,\,x \,-30$ $\,-10\,\,x^2 +\,40\,\,x \,-30$ $\,-10\,\,x^2 +\,20\,\,x \,-30$ $\,10\,\,x^2 \,-20\,\,x \,-30$

$(\,2\,-3\,b)\;(\,-1\,-\,b) = $   ?

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