Find the smallest of three consecutive positive integers if the product of the smaller two
integers is 2 more than 8 times the largest integer.

Respuesta :

Answer:

9

Step-by-step explanation:

Let the three consecutive positive integers be:

  • x
  • x + 1
  • x + 2

If the product of the two smaller integers is 2 more than 8 times the largest integer then:

[tex]\implies x(x+1)=8(x+2)+2[/tex]

Solve the equation for x:

[tex]\implies x^2+x=8x+16+2[/tex]

[tex]\implies x^2+x=8x+18[/tex]

[tex]\implies x^2-7x-18=0[/tex]

[tex]\implies x^2-9x+2x-18=0[/tex]

[tex]\implies x(x-9)+2(x-9)=0[/tex]

[tex]\implies (x+2)(x-9)=0[/tex]

Therefore:

[tex]\implies x+2=0 \implies x=-2[/tex]

[tex]\implies x-9=0 \implies x=9[/tex]

As x is a positive integer, x = 9.