Abag contains blue marbles and red marbles, 47 in total. the number of blue
marbles is 9 less than 3 times the number of red marbles. how many blue marbles
are there?

N=14

Step-by-step explanation:

n+(3n-9)=47

Combine (In this case add like terms)

4n-9=47 (Move the constant to the right, in this case -9 will change to +9)

4n=47+9 (Add like terms 47+9=56)

4n=56 (Divide both sides by 4)

Divide 56 by 4

56/4=14

n=14

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6