Step-by-step explanation:

[tex]x2 + 12 - 7 = 0[/tex] subtract the number

[tex]x2 + 5 = 0[/tex]

move the constant to the right-hand side and change it's signed

[tex]x { }^{2} = - 5[/tex]

take the square root of both sides of the equation and remember to use both positive and negative roots

[tex]x = + \sqrt{5l} [/tex]

write the solutions,one with a+sign and one with a-sign

[tex]x = - \sqrt{5l \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \x = \sqrt{5l} } [/tex]

the equation has 2 solutions

answer:

[tex]x1 = - \sqrt{5x2 = \sqrt{5l} } [/tex]