the sum of the lengths of two opposite sides of the circumscribed quadrilateral is 10 cm, and its area is 12 cm2. find the radius of the inscribed circle.

1.2 cm

Step-by-step explanation:

Quadrilateral circumscribing a circle is a quadrangle whose sides are tangent to a circle inside it (see attached diagram).

The area of circumscribed quadrilateral is

where is semi-perimeter and r is radius of inscribed circle.

In your case,

If a quadrilateral is circumscribed over the circle, then the sum of opposite sides is equal, so

so

Now

the difference between a number and 5 is -2.

step-by-step explanation:

notice that the equation you are given has -2 (negative 2) on the right side, not 2. when you subtract 5 from a number n, you are finding the difference between the number and 5.

the difference between a number and 5 is -2.

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer