In a compression or longitudinal wave, the particles of the medium are displaced in a direction to the direction of energy transport. a) parallel b) opposite c) perpendicular d) at right angles

Option C is correct

(20, 16)

Step-by-step explanation:

As per the statement:

Mira picked two numbers from a bowl. The difference of the two numbers was 4, and the sum of one-half of each number was 18

System of equation is given as:

           .....[1]

                                          .....[2]

Multiply both sides by 2 in [1] we have;

            ....[3]

Add equations [2] and [3] we have;

2x = 40

Divide both sides by 2 we have;

x = 20

Substitute the value of x in [2] we have;

20-y = 4

Subtract 20 from both sides we have;

-y = -16

Divide both sides by -1 we have;

y = 16

therefore, the two numbers did Mira pick is, (20, 16)