1. What is a solution to the following inequality?

**(x**^{2}+ y^{2}−16)·(x^{2}+ y^{2}− 36) < 02. What is the area S of the part of a coordinate plane defined by the following inequality?

**(x**^{2}+ y^{2}− 25)·(x^{2}+ y^{2}− 49) > 03. What is the area S of the part of a coordinate plane defined by the following system of inequalities?

**x**

y − x < 0^{2}+ y^{2}− 4 < 0y − x < 0

4. What is the perimeter P of the part of a coordinate plane defined by the following system of inequalities?

**x**

y^{2}− 4 < 0y

^{2}− 16 < 05. What is the perimeter P of the part of a coordinate plane defined by the following system of inequalities?

**x**

x + y < 0^{2}+ y^{2}− 9 < 0x + y < 0

6. The part of a coordinate plane is defined by the following inequalities?

**x**

y − |x| < 0^{2}+ y^{2}− R^{2}< 0y − |x| < 0

What is the value of parameter R, if the area of thus defined part of a coordinated plane equals to 48π?