Question

y varies jointly as x and z. If y = 12 when x = 4 and z = 3, find y when x = 9 and z = 8.

Answer 1

Step-by-step explanation:

y=12

x=4

z=3

from the above we can understand that

x*z = y

=>4*3 =12

similarly,

x*z =y

=>9*8=72

therefore the answer is 72

HOPE ITS HELPFUL

Answer 2

Given:

y varies jointly as x and z. If y = 12 when x = 4 and z = 3

To Find:

find y when x = 9 and z = 8

Solution:

Here we will be using the proportionality properties as it is said in the sum that y varies directly with x and z we will put directly to y and, which will go as

$y\propto x\\y\propto z$

now combining both the proportionalities we have,

$y\propto xz$

Now when we remove the proportionality sign a constant is added to the equation, so here it will go as

$y=a*xz$

where a is the constant now when we put the given value of y,x,z in this equation we will get the value of 'a'

$y=a*xz\\12=a*4*3\\a=1$

Now using this constant value we can find the value of y when x=9 and z=8

$y=a*xz\\y=1*9*8\\=72$

Hence, the value of y when x=9 and z=8 is 72.