Quick variation question... y varies jointly with w and..?

Question

Y varies jointly with w and x and inversely with z. Y=360 when x=8 and z=5. Write an equation that models the relationship (i.e. y=...)

Also, if possible find y when w=4, x=4. and z=3.

Thanks so much. Just explain how to do this or provide ANY insight.

eek those arent part of the answer choices....


A] y=9wx/z; 48
B]y=5z/wx; 15
C]y=5wx/z; 80/3
D]y=9z/wx; 27/16

any of those look ok?

Answer 1

Y varies jointly with w and x and inversely with z.

Y = wx/z
this is true but there might be a constant difference
eg R=3P/Q (R is proportional to P but inversely to Q)

so let the constant be K
giving
Y= Kwx/z

sub x=8 z=5 and Y=380
to give
380= Kw(8)/5
Kw= 237.5 <<<< w is the variable and K is constant

sub w=4 x=4 z=3 in Y= Kwx/z & Kw= 237.5
Y= K(4)(4)/(3) = 16K/3
Kw= 237.5 = K(4) >>>> K = 59.375

hence Y = 16K/3 = 16*59.375 / 3 = 316.167

i hope that is right
:)

Answer 2

a million) Simplify: {(a^2-5a+6)^-a million/(a-2)^-2}/{(a-3... I even have been given (a million)/(a-2) you're proper. _____________________________ 2) hit upon the suitable answer(s): x² + 2y² = 33 x² + y² - 19 = 2x x² + 2y² = 33 x² - 2x + y² = 19 Subtract 2 cases the 2d equation from the 1st. -x² + 4x = -5 x² - 4x - 5 = 0 (x + a million)(x - 5) = 0 x = -a million,5 Plug one fee back into between the equations. x² + 2y² = 33 (-a million)² + 2y² = 33 a million + 2y² = 33 2y² = 32 y² = sixteen y = ±4 So we've (x,y) = (-a million,-4) and (-a million,4) Plug distinctive fee back into between the equations. x² + 2y² = 33 5² + 2y² = 33 25 + 2y² = 33 2y² = 8 y² = 4 y = ±2 So we've (x,y) = (5,-2) and (5,2) In total we've 4 answer factors. (x,y) = (-a million,-4); (-a million,4); (5,-2) and (5,2) _______________ 3) 5|3x - 4| = x + a million Rewrite 5|3x - 4| - x - a million = 0 For x ? 4/3 5(3x - 4) - x - a million = 0 15x - 20 - x - a million = 0 14x - 21 = 0 14x = 21 x = 21/14 = 3/2 For x < 4/3 5(-3x + 4) - x - a million = 0 -15x + 20 - x - a million = 0 -16x + 19 = 0 16x = 19 x = 19/sixteen x = 19/sixteen or 3/2 ____________________ 4) ([3]/[5d])/([-9]/[15df]) I even have been given -f you're proper.

Answer 3

Y=k*w*x/z
360=k*w*8/5 so k*w= 225
At w=4 x=4 z=3 as kw always =225
4k=225 so k= 56.25
Y= 56.25*w*x/z
so
Y = 225*4/3 =300