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1.Simplify ( x +1)(x- 1) + 2x ²
2. Simplify (x + 2)(x - 1) -2(x + 1)
3. If 45 is added to a certain number and the result is divided by 9 ,the quotient is 8. What is the number?

Please help

Respuesta :

marlinhadryelle1919

Answer:

Step-by-step explanation:

1)

(x*1) * (x-1) + 2[tex]x^{2}[/tex] = [tex]x^{2} - 1^{2} + 2x^{2}[/tex] = [tex]3x^{2} - 1[/tex]

2)

(x+2) * (x-1) - 2 * (x+1) = [tex]x^{2} - x + 2x - 2 - (2x + 2) = x^{2} + x - 2 - 2x - 2 = x^{2} - x - 4[/tex]

3)

[tex]\frac{x + 45}{9} = 8\\\\x + 45 = 9 * 8= 72\\x = 72 - 45 = 27[/tex]

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