Question

The value of y varies directly with x2, and y = 36 when x = 3.

What is the value of y when x = 5?

Answer 1

@TheSmartOne

Answer 2

@amistre64

Answer 3

whats your direct variation setup?

Answer 4

Is it y=5? im lost

Answer 5

it would be useful to start at the beginning so that we have a firm grasp on how to obtian a solution.

how do we set it up?

Answer 6

y=x5 ?

Answer 7

direct variation means that when y increases, x increases .... y = kx^2

another way of writing this is ...

y/x^2 is constant for all (x,y)

36/3^2 = y/5^2

what is y?

Answer 8

I got 4 by dividing 36 by 9

Answer 9

good

now keep going

4 = y/25

Answer 10

How do i find Y?

Answer 11

Would it be 5?

Answer 12

is 5/25 = 4? no

Answer 13

this is basic arithmetic ...

Answer 14

multiply each side by ... what?

Answer 15

4?

Answer 16

no .... at least not effectively

is 25/25 = 1?

Answer 17

yes

Answer 18

4 = y/25

4(25) = y(25/25)
this is 1

4(25) = y*1

what can we conclude?

Answer 19

That y is 100?

Answer 20

y is divided into 25 parts y/25 and

4 is equal to 1/25th of y

if we add up all 25 parts of y, we get 1 y ...

adding up 25 parts that are each equal to 4 is just: 4(25) = 100 yes

Answer 21

Is that all?

Answer 22

thats all the question requires ...

Answer 23

Thank you

Answer 24

youre welcome