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Just substitute? (Posted on 2019-09-17)

Find the value of x⁵-100x⁴+100x³-100x²+100x-9 when x = 99.

No Solution Yet Submitted by Danish Ahmed Khan

Rating: 3.0000 (2 votes)

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Solution

| Comment 1 of 3

x^5-100x^4+100x^3-100x^2+100x-9

= (x^5-99x^4) + (-x^4+99x^3) + (x^3-99x^2) + (-x^2+99x) + x-9

= (x-99)*(x^4-x^3) + (x-99)*(-x^3+x^2) + (x-99)*(x^2-x) + (x-99)*(-x+1) + x-9

= 0*(99^4-99^3) + 0*(-99^3+99^2) + 0*(99^2-99) + 0*(-99+1) + 99-9

= 90

Posted by Brian Smith on 2019-09-17 13:04:10

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