InterviewSolution
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InterviewSolution
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Simplify combining like terms :(i) 21b – 32 + 7b – 20b(ii) z2 + 13z2 – 5z + 7Z2 – 15z(iii) p – (p – q) – q – (q – p)(iv) 3a – 2b – ab – (a – b + ab) + 3ab + b – a(v) 5x2y – 5x2 + 3yx2 – 3y2 + x2 – y2 + 8xy2 – 3y2(vi) (3y2 + 5y – 4) – (8y – y2 – 4) . |
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Answer» (i) 21b – 32 + 7b – 20b (re-arranging the terms) = 21b + 7b – 20b – 32 = 28b – 20b – 32 = 8b – 32 (ii) z2 + 13z2 – 5z + 7Z2 – 15z (re-arranging the terms) = -z2 + 13z2 – 5z – 15z + 7z3 = 12z2 – 20z + 7z3 (iii) p – (p – q) – q – (q – p) = p – p + q – q – q + p (re-arranging the terms) = p + p - p + q - q - q = p – q (iv) 3a – 2b – ab – (a – b + ab) + 3ab + b – a = 3a – 2b – ab – a + b – ab + 3ab + b – a = 3a – a – a – 2b + b + b – ab – ab + 3ab = 3a - 2a - 2b + 2b - 2ab + 3ab = a + ab (v) 5x2y – 5x2 + 3yx2 – 3y2 + x2 – y2 + 8xy2 – 3y2 (re-arranging the terms) = 5x2y + 3yx2 – 5x2 + x2 – 3y2 – y2 – 3y2 + y2 = 8x2y – 4x2 – 7y2 + 8xy2 (vi) (3y2 + 5y – 4) – (8y – y2 – 4) . 3y2 + 5y – 4 – 8y – y2 – 4 (re-arranging the terms) 3y2 + y2 + 5y – 8y – 4 + 4 = 14y2 – 3y |
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