$1.$ Por factorizaciòn. $2$ Utilizando la formula. 1. $x^{2}-7x+12=0$ $2$ $x^{2}-9x+18=0$ 3. $x^{2}+6x=-9$ 4. $2x^{2}+10x-48=0$ $5$ $x^{2}=-9x+15$ 6. $5x^{2}=125$ 7 $x^{2}-8x=0$ $8$ $9x^{2}-x=0$ $9$ x2 $7x+12=20x^{2}+x+1$ 10 $\left(x-1\right)\left(x+2\right)=0$ 11. $\left(=x-1\right)\left(x+10\right)+12=7$ 3. 12 $-1$ $+-x=$ 16 8.

$1.$ Por factorizaciòn. $2$ Utilizando la formula. 1. $x^{2}-7x+12=0$ $2$ $x^{2}-9x+18=0$ 3. $x^{2}+6x=-9$ 4. $2x^{2}+10x-48=0$ $5$ $x^{2}=-9x+15$ 6. $5x^{2}=125$ 7 $x^{2}-8x=0$ $8$ $9x^{2}-x=0$ $9$ x2 $7x+12=20x^{2}+x+1$ 10 $\left(x-1\right)\left(x+2\right)=0$ 11. $\left(=x-1\right)\left(x+10\right)+12=7$ 3. 12 $-1$ $+-x=$ 16 8.

a) $x^{n}-7x+12=0$ b) $x^{n}-9x+18=0$ $N0ta^{°}$ las comillas son el número $2$ $n=2$