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    Question

    when x =5 and y =-7 then find the value of 27x³ +58x²y

    +31xy² +8y³?
    A 1224 Correct Answer Incorrect Answer
    B 1924 Correct Answer Incorrect Answer
    C -1924 Correct Answer Incorrect Answer
    D 1724 Correct Answer Incorrect Answer

    Solution

    27x³ +58x²y +31xy² +8y³ =27x³ +54x²y + 4x²y +36xy²-5 xy² +8y³ =(3x+2x) ³ +4x²y -5 xy² =[3×5+2×(-7)]³ + 4×25×(-7)-5×5×49 =1-700-1225 =1-1925 = -1924

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