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when x^2+ax-b is divided by x+2, the remainder is -7.
when ax^2-bx+1 is divided by x-2,the remainder is 3.
find the values of a and b.

係咪應該用remainder theorem...但係我計唔到…

just use remainder theorem, two eqs, two unknowns.
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when x^2+ax-b is divided by x+2, the remainder is -7.

sub x = -2, get 4-2a-b = -7
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when ax^2-bx+1 is divided by x-2, the remainder is 3.

sub x = 2, get 4a-2b+1 = 3

then do it yourself

引用第1樓kylau於2007-06-04 21:58發表的“”:
just use remainder theorem, two eqs, two unknowns.
----------
when x^2+ax-b is divided by x+2, the remainder is -7.
sub x = -2, get 4-2a-b = -7
.......

thz...而家試下先

計到了...
a=3 , b=5
岩岩諗錯方向攪到計唔到…
thz kylau

用計數機程式咪得lo..