Question

efetue os calculos pedidos

a] 9 x2 y3 - 31 xy + 16 ab 2 + { 10 x2 y3 - 15 xy + 27ab 2]

b] - ab ;50 ab2 - [3ab + 18 ab2]

c]13 x4 + 28 y3 + [-13x4 - 28 y3 + 67

Answer 1

$9x\cdot \:2y\cdot \:3-31xy+16ab\cdot \:2+10x\cdot \:2y\cdot \:3-15xy+27ab\cdot \:2\\\\=9\cdot \:2\cdot \:3xy-46xy+16\cdot \:2ab+10\cdot \:2\cdot \:3xy+27\cdot \:2ab\\\\=54xy-46xy+32ab+60xy+54ab\\=54xy-46xy+60xy+32ab+54ab\\\\=54xy-46xy+60xy+86ab\\\\=68xy+86ab$

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$-\:ab\:;50\:ab2\:-\:\left[3ab\:+\:18\:ab2\right]\\\\\mathrm{Fatorar\:}-ab\\\\50ab\cdot \:2-\left(3ab+18ab\cdot \:2\right)\\\\=100ab-39ab\\\\=ab\left(100-39\right)\\\\=61ab\\\\-61\cdot \:a\cdot \:b$

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$13x\cdot \:4+28y\cdot \:3+\left(-13x\cdot \:4-28y\cdot \:3+67\right)\\\\=13x\cdot \:4+28y\cdot \:3-13x\cdot \:4-28y\cdot \:3+67\\\\=28\cdot \:3y-28\cdot \:3y+67\\\\=67$