Question

допоможіть будь ласка. ​

Answer 1

1)

$b {}^{2} - 4b = b(b - 4)$

1. b = - 2 :

$- 2 \times ( - 2 -4 ) = - 2 \times ( - 6) = 12$

2. b = 0,5 :

$0.5 \times (0.5 - 4) = 0.5 \times ( - 3.5) = - 1.75$

2)

${x}^{2} - {y}^{2} = (x - y)(x + y)$

1. x = 5 ; y = - 3 :

$(5 - ( - 3))(5 + ( - 3)) = (5 + 3)(5 - 3) = 8 \times 2 = 16$

2. x = 0,1 ; y = 0,2 :

$(0.1 - 0.2)(0.1 + 0.2) = - 0.1 \times 0.3 = - 0.03$