7.已知定点P(-2,0)和直线l:(1+3λ)x+(1+2λ)y-(2+5λ)=0,λ∈R,则点P到直线l的距离d的最大值为( )
| A. | 2$\sqrt{3}$ | B. | $\sqrt{10}$ | C. | $\sqrt{14}$ | D. | 2$\sqrt{5}$ |
6.若变量x,y满足约束条件$\left\{\begin{array}{l}{x+y≥1}\\{y-x≤1}\\{x≤1}\end{array}\right.$,则$\frac{y+1}{x}$的最小值是( )
0 233580 233588 233594 233598 233604 233606 233610 233616 233618 233624 233630 233634 233636 233640 233646 233648 233654 233658 233660 233664 233666 233670 233672 233674 233675 233676 233678 233679 233680 233682 233684 233688 233690 233694 233696 233700 233706 233708 233714 233718 233720 233724 233730 233736 233738 233744 233748 233750 233756 233760 233766 233774 266669
| A. | 0 | B. | 1 | C. | -1 | D. | 3 |