B) Dalam Rajah 2.1, PORS dan STUV ialah segi empat tepat. In Diagram 2.1, PORS and STUV are rectangles.
7
S
9
(2h + 1) cm
V
(3k - 1) cm
R
Rajah 2.1
Diagram 2.1
Ungkapkan luas, dalam cm, kawasan yang berlorek dalam sebutan x dan y.
Express the area, in cm², of the shaded region in terms of x and y.
Jawapan/

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

explanation:

previous steps have made pa≅ pb ≅ st ≅ su. setting the compass width to ab allows you to make tu the same length. then δstu ≅ δpab by the sss congruence postulate, and ∠p ≅ ∠s by the reason cpctc.

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source:  

what are the answer choices given for this problem?