Math

Question Find yy when yy varies directly as xx, and y=18y=18 when x=5x=5, given x=11x=11.

Studdy Solution

STEP 1

Assumptions
1. The relationship between yy and xx is a direct variation.
2. The value of yy is 18 when xx is 5.
3. We need to find an expression to calculate the value of yy when xx is 11.

STEP 2

The general equation for direct variation is y=kxy = kx, where kk is the constant of variation.

STEP 3

Using the given values of yy and xx, we can find the constant of variation kk.
18=k518 = k \cdot 5

STEP 4

Solve for kk by dividing both sides of the equation by 5.
k=185k = \frac{18}{5}

STEP 5

Now that we have the constant of variation kk, we can write the general equation for yy in terms of xx.
y=185xy = \frac{18}{5}x

STEP 6

To find the value of yy when xx is 11, we substitute 11 for xx in the equation.
y=18511y = \frac{18}{5} \cdot 11

STEP 7

Multiply to find the value of yy.
y=18511=18115y = \frac{18}{5} \cdot 11 = \frac{18 \cdot 11}{5}

STEP 8

The expression that can be used to find the value of yy when xx is 11 is:
y=185(11)y = \frac{18}{5}(11)
Therefore, the correct expression is y=185(11)y=\frac{18}{5}(11).

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord