Factorisation

Factorise fully: $x^{2}-36$

Factorise fully: $x^{2}-11x+28$

Factorise fully: $8x^{2}+4x$

Factorise fully: $x^{2}-5x+6$

Factorise fully: $x^{2}+10x+21$

Factorise fully: $x^{2}-4$

Factorise fully: $4x^{2}-16$

Factorise fully: $8x^{2}+12x$

Factorise fully: $x^{2}+2x-3$

Factorise fully: $9x^{2}-16$

Factorise fully: $x^{2}+x-42$

Factorise fully: $9x^{2}-81$