Christina collects stamps. she has 47 stamps in all. she has 20 stamps from europe. the number of african stamps is 2 times the number of asian stamps. how many stamps from each of these three continents does she have? use reasoning to write this as a numerical expression.

20 stamps from Europe

18 stamps from Asia

9 stamps from Afrca

Step-by-step explanation:

Let

x=number of Europe stamps

y=number of Africa stamps

This implies that

2y=Number of Asia stamps

She has 47 stamps in all implies that

x+y+2y=47

20+3y=47

3y=47-20

3y=27

y=9

right

step-by-step explanation:

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x