Respuesta :

altavistard

Answer:

{-1, 10}

Step-by-step explanation:

Next time please share the entire set of instrutions.

x^2 - 9x - 15 = -5 should be rewritten in standard quadratic form:

x^2 - 9x - 10 = 0 = (x - 10)(x + 1) = 0.

Setting each factor equal to zero and then solving for x yields {-1, 10}

pc192y

Answer:

{-1,10}

Step-by-step explanation:

[tex]x^2-9x-15=-5[/tex]   given

[tex]x^2-9x-10=0[/tex]   addition property of equality

[tex]x^2+(x-10x)-10=x^2+x-10x-10=0[/tex]   x-10x = -9x

[tex]x(x+1)-10(x+1)=0[/tex]   distributive property ( x( y + z ) = xy + xz

[tex](x-10)(x+1)=0[/tex]   distributive property (backwards)

[tex]x-10=0;x=10;x+1=0;x=-1[/tex]   at least one factor of 0 has to be 0

{-1,10}

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