Suppose y varies jointly as x and z. find y when x = 5 and z = 16, if y = 136 when x = 5 and z = 8. round your answer to the nearest hundredth, if necessary.

The value of y when x = 5 and z = 16 is 272

Step-by-step explanation:

* Lets Talk about the direct variation

- y is varies jointly (directly) as x and z, that means there are direct

  relation between y , x and z

- y increases if x increases or z increases

∴ y ∝ x × z

- To change this relation to equation we use a constant k

∴ y = k (x) (z), where k is the constant of variation

- To find the value of k we substitute the values of x , y and z in

  the equation above

∵ y = 136 when x = 5 and z = 8

∴ 136 = k × 5 × 8

∴ 136 = 40 k ⇒ divide both sides by 40

∴ k = 3.4

- Substitute this value in the equation

∴ y = 3.4 (x) (z)

∵ x = 5 , z = 16

∴ y = 3.4 (5) (16) = 272

∴ The value of y when x = 5 and z = 16 is 272

The correct answer is B.

Step-by-step explanation:

If y varies jointly as x and z, then we can write the join variation equation.

, where 'k' is the constant of proportionality.

If y = 136 when x = 5 and z = 8,then

,

.

The variation equation now becomes:

when x = 5 and z = 16, then

The correct answer is B.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.