Алгебра, 20 баллов а) 3х-4(х+1) 7х-23 в)х2 -5х-6

Пошаговое объяснение:

А)

- 4 \\ x > 1.5" alt="3x - 4(x + 1) < 8 + 5x \\ 3x - 4x - 4 < 8 + 5x \\ - x - 5x < 8 - 4 \\ - 6x < 4 \\ 6x > - 4 \\ x > 1.5" align="absmiddle" class="latex-formula">

Б)

7x - 23 \\ 2x - 7x > - 23 + 76 \\ - 5x > 53 \\ 5x < 53 \\ x < 10.6" alt="2x - 76 > 7x - 23 \\ 2x - 7x > - 23 + 76 \\ - 5x > 53 \\ 5x < 53 \\ x < 10.6" align="absmiddle" class="latex-formula">

В)

${x}^{2} - 5x - 6 < 0 \\ {x}^{2} - 5x - 6 = 0 \\ \sqrt{d} = \sqrt{25 - 4 \times 1 \times ( - 6)} = 1 \\ x_{1} = \frac{5 + 1}{2} = 3 \\ x_{2} = \frac{5 - 1}{2} = 2 \\ 2 < x < 3$