Which expression represents, twice the difference of two numbers?

(a) 2(x−y)

(b) 2−x−y

(c) 2x−y

(d) 2(x+y)

A

Step-by-step explanation:

The difference of two numbers x and y is x - y

Twice this difference is

2(x - y) → A

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