Question

Simplifique as expressões:

a)
$(x - 4)^{2} - (x - 1)^{2}$
b)
$( - x + 3)^{2} - 2x(4 - x)$

Answer 1

a)
${(x - 4)}^{2} - {(x - 1)}^{2}$

${x}^{2} - 8x + 16 - {(x}^{2} - 2x + 1)$

${x}^{2} - 8x + 16 - {x}^{2} + 2x - 1$

$- 6x + 15$

b)
${( - x + 3)}^{2} - 2x \times (4 - x)$

${(3 - x)}^{2} - 8 + {2x}^{2}$

$9 - 6x + {x}^{2} - 8x + {2x}^{2}$

$9 - 14x + {3x}^{2}$

$3 {x}^{2} - 14x + 9$