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    If ax^2 + bx + c = Lx^2 + mx + n , the values of the two quadratics are the same for all values of x. By applying this with x=0,x=-1 and x=1, deduce that a=1,b=m and c=n.
    I figured out the answer for c=n by using x=0 but not sure for x=-1 and x=1.
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    (Original post by Chelsea12345)
    If ax^2 + bx + c = Lx^2 + mx + n , the values of the two quadratics are the same for all values of x. By applying this with x=0,x=-1 and x=1, deduce that a=1,b=m and c=n.
    I figured out the answer for c=n by using x=0 but not sure for x=-1 and x=1.
    Strange question. There are easier ways to see that a = L, b = m and c = n.

    Anyway, once you substitute x=1 and x=-1 into both sides you should end up with two equations. Try adding the equations together and see what happens. Please post your working if you get stuck.

    (I'm assuming you meant a = L instead of a = 1).
 
 
 
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