Question

determine as seguintes somas algébricas :


$\frac{1}{2} x^{2} - \frac{2}{5} {x}^{2}$
$- {xy}^{2} + 7 {xy}^{2}$
$2abc - \frac{1}{5} bc$




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Answer 1

Resposta:

1.

$\frac{1}{2} x^{2} - \frac{2}{5} {x}^{2} \\ {x}^{2} ( \frac{1}{2} - \frac{2}{5} ) \\ {x}^{2} ( \frac{5 \times 1 - 2 \times 2}{10} ) \\ {x}^{2} ( \frac{5 - 4}{10} ) \\ \frac{1}{10} {x}^{2}$

2.

$- {xy}^{2} + 7 {xy}^{2} \\ x {y}^{2} ( - 1 + 7) \\ x {y}^{2} (6) \\ 6x {y}^{2}$

3.

$2abc - \frac{1}{5} bc \\ bc(2a - \frac{1}{5} ) \\ bc( \frac{5 \times 2a - 1 \times 1}{5} ) \\ bc( \frac{10a - 1}{5} ) \\ \frac{10abc - bc}{5}$

Answer 2

a)

$\frac{1}{2} x { } ^{2} - \frac{2}{5} x {}^{2} \\ \\ \frac{x {}^{2} }{2} - \frac{2x {}^{2} }{5} \\ \\ \frac{5x {}^{2} }{5 \times 2} - \frac{2 \times 2x {}^{2} }{2 \times 5} \\ \\ \frac{5x {}^{2} }{10} - \frac{4x {}^{2} }{10} \\ \\ \frac{5x{}^ {2} - 4x {}^{2} }{10} \\ \\ \frac{1}{1 0} x {}^{2}$