$(-9x+10y)(-9x-10y) = $   ?

$81\,x^2 \,- 100\,y^2$ $-81\,x^2 \,- 100\,y^2$ $81\,x^2 \,- 100y$ $81\,x^2 \,- 20\,y^2$

$(11x+8y)^2 = $   ?

$121\,x^2\, +88\,x\,y\,+ 64\,y^2$ $11\,x^2\, +176\,x\,y\,+ 64\,y^2$ $121\,x^2\, +176x\,+ 64\,y^2$ $121\,x^2\, +176\,x\,y\,+ 64\,y^2$

$(-6y-12x)^2 = $   ?

$-12\,y^2\, +144\,x\,y\,+ 144\,x^2$ $36\,y^2\,- 144\,x^2$ $36\,y^2\, -144\,x\,y\,+ 144\,x^2$ $36\,y^2\, +144\,x\,y\,+ 144\,x^2$

$(-2-6x)^2 = $   ?

$4\, +24\,x\,+ 36\,x^2$ $-4\, +24\,x\,+ 36\,x^2$ $4\, +12\,x\,+ 36\,x^2$ $4\, +24\,x\,+ 6\,x^2$

$(-12x+12y)(-12x-12y) = $   ?

$144\,x^2\, +288\,x\,y\,+ 144\,y^2$ $144\,x^2 \,+ 144\,y^2$ $144x \,- 144\,y^2$ $144\,x^2 \,- 144\,y^2$

$(6y+5x)^2 = $   ?

$6\,y^2\, +60\,x\,y\,+ 25\,x^2$ $36\,y^2\, +60\,x\,y\,+ 25\,x^2$ $36\,y^2\, +60\,x\,y\,+ 10\,x^2$ $36\,y^2\, +60\,x\,y\,+ 5\,x^2$