Question

The variables y and x have a proportional relationship, and y = 7 when x = 2. What is the value of y when x = 5? Enter your answer as a decimal in the box.

Answer 1

y = 17.5

Explanation:

A relationship between two variables, x, and y, represent a direct variation if it can be expressed in the form y/x = k or y = kx

Find the value of the constant k

we have:

y = 7 and x = 2

substitute

7/2 = k

k = 3.5

Thus, the equation is equal to

y = 3.5x

Find the value of y when x = 5

substitute in the equation

y = 3.5(5) = 17.5

Or we can put as:

y = 7 * 5 /2

Calculate the product or quotient: y = 35/2

Answer = 17.5

[RevyBreeze]

Answer 2

y = 17.5

Explanation:

If y is proportional to x, then:

`y = kx` (for some constant k)

Given y = 7 when x = 2:

⇒ 7 = 2k

⇒ k = 3.5

Therefore,
`y=3.5x`

So when x = 5:

⇒ y = 3.5 x 5

⇒ y = 17.5