Yvaries jointly as x and z. y equals 70 when x equals 7 and z equals 2. find y when x equals 6 and z equals 4. y= ?

Hello from MrBillDoesMath!

 y = 120

Discussion:

"y varies jointly as x and  z"  ==>    y = k*x*z   where k is a constant

Substitute y = 70, x = 7, z = 2 in this equation to determine the value of k

y     = k *x * z

70   = k * 7 * 2   or

70 = 14k or

k = 5.

So  y = 5 *x * z is the equation of variation.

Substituting x = 6 and z =4 in the equation gives

y = 5 * x * z = 5 * 6 * 4 = 120

Thank you,

MrB

step-by-step explanation:

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2