Question

a) (2x + 1)(10x - 7)>=0;​

Answer 1

Ответ:

$(2x+1)*(10x-7)\geq 0$

$\left \{ {{2x+1\geq 0} \atop {10x-7\geq 0}} \right.$

$\left \{ {{2x+1\leq 0} \atop {10x-7\leq 0}} \right.$

$\left \{ {{x\geq -\frac{1}{2} } \atop {x\geq \frac{7}{10} }} \right.$

$\left \{ {{x\leq -\frac{1}{2} } \atop {x\leq \frac{7}{10} }} \right.$

x ∈ ( -∞ , -$\frac{1}{2}$ ] ∪ [ $\frac{7}{10}$ , + ∞ )