Question

Помогите пж срочно!!!!!!!!!!​

Answer 1

Объяснение:

1)

${a}^{2} - 18a + 17 = {a}^{2} - 18a + 17 + 81 - 81 = (a - 9) ^{2} - 64 = (a - 9) ^{2} - 8 ^{2} = (a - 17)(a - 1)$

2)

$- {x}^{2} - 4x + 21 = - {x}^{2} - 7x + 3x + 21 = - x(x + 7) + 3(x + 7) = (3 - x)(7 + x)$

3)

$60 {y}^{2} - 20y - 5 =5( 12 {y}^{2} - 4y - 1 )= 5(12 {y}^{2} - 6y + 2y - 1) =5( 6y(2y - 1) + 1(2y - 1)) = 5(6y + 1)(2 - 1)$

4)

$- \frac{1}{8} {x}^{2} - \frac{3}{4} x + 5 = \frac{1}{8}( - x ^{2} - 6x + 40) = \frac{1}{8}( - {x}^{2} + 4x - 10x + 40) =\frac{1}{8}( x(4 - x) + 10(4 - x) )= \frac{1}{8}(x + 10)(4 - x)$