а)

[tex]( x+ 4) {}^{2} ( x- 9) \geqslant 0 \\ - - - - [ - 4] - - - - [ 9] + + + + \\ x \: \in \: \left\{ - 4\right\}U[9; \: + \infty )[/tex]

б)

[tex](x - 4) {}^{2} (3x + 2) \leqslant 0 \\ (x - 4) {}^{2} (x + \frac{2}{3} ) \leqslant 0 \\ - - - - [ - \frac{2}{3} ] + + + + [4] + + + + \\ x \:\in\: ( - \infty ; \: - \frac{2}{3} ] \: U \left\{4\right\}[/tex]

в)

[tex](6 - x)(x - 3)(4x - 9) \geqslant 0 \\ (x - 6)(x - 3)(x - 2.25) \leqslant 0 \\ - - - - [2.25] + + + + [3] - - - - [6] + + + + \\ x \: \in \: ( - \infty ; \: 2.25]U[3; \: 6][/tex]