$(\,4\,t+\,4)\;(\,1+\,2\,x) = $   ?

$\,20\,\,t^2\,x^2 +\,4$ $\,4\,\,t +\,8\,\,t\,x +\,4 +\,8\,\,x$ $\,5\,\,t +\,6\,\,t\,x +\,5 +\,6\,\,x$ $\,8\,\,t\,x +\,4$

$(\,3\,t+\,5)\;(\,5\,t+\,2) = $   ?

$\,8\,\,t^2 +\,15\,\,t +\,7$ $\,46\,\,t +\,10$ $\,15\,\,t^2 +\,31\,\,t +\,10$ $\,15\,\,t^2 +\,10$

$(\,a+\,4)\;(\,6+\,3\,b) = $   ?

$\,21\,\,a^2\,b^2 +\,24$ $\,7\,\,a +\,4\,\,a\,b +\,10 +\,7\,\,b$ $\,3\,\,a\,b +\,24$ $\,6\,\,a +\,3\,\,a\,b +\,24 +\,12\,\,b$

$(\,a+\,1)\;(\,a+\,3) = $   ?

$\,\,a^2 +\,4\,\,a +\,3$ $\,2\,\,a^2 +\,6\,\,a +\,4$ $\,5\,\,a +\,3$ $\,\,a^2 +\,3$

$(\,5\,-6\,a)\;(\,6+\,b) = $   ?

$\,-30 +\,5\,\,b \,-36\,\,a \,-6\,\,a\,b$ $\,30 \,-5\,\,b \,-36\,\,a \,-6\,\,a\,b$ $\,30 +\,5\,\,b \,-36\,\,a \,-6\,\,a\,b$ $\,-30 +\,5\,\,b +\,36\,\,a \,-6\,\,a\,b$

$(\,3\,x\,-5)\;(\,-\,y+\,2) = $   ?

$\,-3\,\,x\,y +\,6\,\,x \,-5\,\,y \,-10$ $\,-3\,\,x\,y +\,6\,\,x +\,5\,\,y \,-10$ $\,-3\,\,x\,y \,-6\,\,x \,-5\,\,y \,-10$ $\,-3\,\,x\,y \,-6\,\,x +\,5\,\,y +\,10$

$(\,4\,-5\,a)\;(\,a+\,2) = $   ?

$\,-5\,\,a^2 \,-6\,\,a +\,8$ $\,-5\,\,a^2 \,-14\,\,a \,-8$ $\,-5\,\,a^2 +\,14\,\,a \,-8$ $\,5\,\,a^2 \,-14\,\,a +\,8$

$(\,4\,a\,-3)\;(\,-5\,b\,-2) = $   ?

$\,-20\,\,a\,b \,-8\,\,a +\,15\,\,b +\,6$ $\,-20\,\,a\,b \,-8\,\,a \,-15\,\,b \,-6$ $\,-20\,\,a\,b \,-8\,\,a \,-15\,\,b +\,6$ $\,-20\,\,a\,b +\,8\,\,a \,-15\,\,b +\,6$

$(\,3+\,3\,a)\;(\,-6\,-\,a) = $   ?

$\,3\,\,a^2 \,-15\,\,a \,-18$ $\,-3\,\,a^2 \,-21\,\,a \,-18$ $\,-3\,\,a^2 \,-21\,\,a +\,18$ $\,-3\,\,a^2 +\,15\,\,a \,-18$

$(\,6\,-6\,x)\;(\,-5\,x\,-2) = $   ?

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