$(\,5+\,4\,x)\;(\,6+\,5\,y) = $   ?

$\,69\,\,x^2\,y^2 +\,30$ $\,30 +\,25\,\,y +\,24\,\,x +\,20\,\,x\,y$ $\,11 +\,10\,\,y +\,10\,\,x +\,9\,\,x\,y$ $\,20\,\,x\,y +\,30$

$(\,6+\,4\,y)\;(\,5\,y+\,1) = $   ?

$\,20\,\,y^2 +\,6$ $\,20\,\,y^2 +\,34\,\,y +\,6$ $\,54\,\,y +\,6$ $\,9\,\,y^2 +\,16\,\,y +\,7$

$(\,5+\,4\,t)\;(\,2\,x+\,5) = $   ?

$\,7\,\,x +\,10 +\,6\,\,t\,x +\,9\,\,t$ $\,10\,\,x +\,25 +\,8\,\,t\,x +\,20\,\,t$ $\,38\,\,t^2\,x^2 +\,25$ $\,8\,\,t\,x +\,25$

$(\,2+\,4\,t)\;(\,3+\,6\,t) = $   ?

$\,24\,\,t^2 +\,6$ $\,24\,\,t^2 +\,24\,\,t +\,6$ $\,10\,\,t^2 +\,15\,\,t +\,5$ $\,48\,\,t +\,6$

$(\,5+\,2\,t)\;(\,4\,-\,x) = $   ?

$\,-20 \,-5\,\,x \,-8\,\,t \,-2\,\,t\,x$ $\,20 \,-5\,\,x +\,8\,\,t \,-2\,\,t\,x$ $\,20 \,-5\,\,x +\,8\,\,t +\,2\,\,t\,x$ $\,-20 \,-5\,\,x +\,8\,\,t \,-2\,\,t\,x$

$(\,2\,b\,-2)\;(\,a\,-6) = $   ?

$\,-2\,\,a\,b +\,12\,\,b \,-2\,\,a +\,12$ $\,2\,\,a\,b \,-12\,\,b \,-2\,\,a +\,12$ $\,2\,\,a\,b +\,12\,\,b \,-2\,\,a \,-12$ $\,2\,\,a\,b \,-12\,\,b \,-2\,\,a \,-12$

$(\,3\,y+\,1)\;(\,-\,y+\,5) = $   ?

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

$(\,3\,-6\,b)\;(\,-4\,-5\,a) = $   ?

$\,12 \,-15\,\,a +\,24\,\,b +\,30\,\,a\,b$ $\,-12 \,-15\,\,a +\,24\,\,b +\,30\,\,a\,b$ $\,-12 +\,15\,\,a +\,24\,\,b +\,30\,\,a\,b$ $\,12 +\,15\,\,a +\,24\,\,b +\,30\,\,a\,b$

$(\,3\,-\,y)\;(\,-5\,y+\,6) = $   ?

$\,5\,\,y^2 \,-9\,\,y \,-18$ $\,5\,\,y^2 \,-21\,\,y +\,18$ $\,-5\,\,y^2 \,-21\,\,y +\,18$ $\,5\,\,y^2 +\,9\,\,y +\,18$

$(\,4\,-\,x)\;(\,-\,x\,-2) = $   ?

$\,\,x^2 +\,6\,\,x \,-8$ $\,\,x^2 \,-2\,\,x \,-8$ $\,\,x^2 +\,2\,\,x \,-8$ $\,-\,\,x^2 \,-2\,\,x \,-8$