$1.x^{2}-x-6$ - $x^{2}-3x-18$ $2.$ = $3.x^{2}-5x-14$ - $4$ $2$ $x-3x-4$ $5.x^{2}-2x-24$ $=$ $6.x^{2}-7x-8$ $=$ $7$ $x^{2}-2x-3$ $=$ $8.x^{2}-2x-15$ $=$ $9.x^{2}-4x-12$ $=$ $x^{2}-9x-36$ $10.$ $=$

$12\right)$ $x^{2}-18x+81$ $14\right)$ $x^{2}-x-72$ $=$ $16\right)$ $x^{2}+13x+12$ - $18\right)$ $x^{2}-20x-21$ $=$ $20\right)$ $x^{2}+x-6$ $=$ $22\right)$ $x^{2}+9x+18$ $24\right)$ $x^{2}+x-90$ $=$

$6$ $4x^{2}-$ $20x$ $=$ $8.$ $27x^{2}-18x$ $=$ $10.$ $x^{2}-11x+30$ $=$ $12.$ $x^{2}-18x+81$ $=$ $2$