Question

Solve the equation below and find the variation constant, k .Find y when x = 7 and z=5, if y varies jointly as x and 2, and y= 14 and x = 4 when z= 3​

Answer 1

Answers:

Variation Constant: k = 7/6

y = 245/6 when x = 7 and z = 5

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Explanation:

"y varies jointly as x and z" means that y = kxz

We have (x,y,z) = (4,14,3) as one triple, so,

y = kxz

14 = k*4*3

14 = 12k

12k = 14

k = 14/12

k = 7/6 is the variation constant

The equation goes from y = kxz to y = (7/6)xz

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Plug in x = 7 and z = 5 to find y

y = (7/6)xz

y = (7/6)*7*5

y = (7/6)*(7/1)*(5/1)

y = (7*7*5)/(6*1*1)

y = 245/6