Question

решить 5.) , 6.), 7.) , 8.) Очень

Answer 1

5

$f(x) = (x + 2x)(x - 5) = 3x(x - 5) = \\ = 3 {x}^{2} - 15x$

$f'(x) = 6x - 15$

6

$f'(x) = (x - 3)'(x + 4) + (x + 4)'(x - 3) = \\ = (x + 4) + (x - 3) = 2x + 1$

7

$f'(x) = ( {(x - 2)}^{2} )'(x + 1) + (x + 1) '{(x - 2)}^{2} = \\ = 2(x - 2)(x + 1) + {(x - 2)}^{2} = (x - 2)(2( x + 1) + (x - 2)) = \\ = (x - 2)(2x + 2 + x - 2) = (x - 2) \times 3x = 3 {x}^{2} - 6x$

8

$f'(x) = 3 {(x + 1)}^{2} = 3 ({x}^{2} + 2x + 1) = \\ = 3 {x}^{2} + 6x + 3$