Question

please send me the answer
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Answer 1

Answer:

$a) {5x}^{2} - 2x + 8$

$b) {4x -}^{2} - {3y}^{2} + 2xy + 9$

$c) {2a}^{3} - {b}^{3} - 3ab + 3b - 5$

Step-by-step explanation:

$a) \: ({2x}^{2} - 3x + 1) + ({3x}^{2} - 2x) + (3x + 7) \\ = {2x}^{2} - 3x + 1 + {3x}^{2} - 2x + 3x + 7 \\ = ({2x}^{2} + {3x}^{2}) + ( - 3x - 2x + 3x) + 1 + 7 \\ = {5x}^{2} - 2x + 8$

$b) ({x}^{2} +2xy + {y}^{2}) + ( {x}^{2} - {3y}^{2} ) + ({2x}^{2} - {y}^{2} + 9) \\ = {x}^{2} + 2xy + {y}^{2} + {x}^{2} - {3y}^{2} + {2x}^{2} - {y}^{2} + 9 \\ = ( {x}^{2} + {x}^{2} + {2x}^{2} ) + ( {y}^{2} - {3y}^{2} - {y}^{2} ) + 2xy + 9 \\ = {4x}^{2} - {3y}^{2} + 2xy + 9$

$c) ({a}^{3} + {b}^{3} - 3) + ({2a}^{3} - {3b}^{3} - 3ab + 7) + ( { - a}^{3} + {b}^{3} + 3ab - 9) \\ = {a}^{3} + {b}^{3} - 3 + {2a}^{3} - {3b}^{3} - 3ab + 7 - {a}^{3} + {b}^{3} + 3b - 9 \\ = ( {a}^{3} + {2a}^{3} - {a}^{3} ) + ( {b}^{3} - {3b}^{3} + {b}^{3} ) - 3ab + 3b - 3 + 7 - 9 \\ = {2a}^{3} - {b}^{3} - 3ab + 3b - 5$