Question

The quantity r varies jointly with t and u and inversely with s when t= -12, u= -7, and s= -4, r= -126. Find r when t= -8, u= 8, and s= -6.
Write your answer in exact form.

Answer 1

Answer:

r = 64

Step-by-step explanation:

r = (k*t*u)/s

Where,

k = constant of proportionality

t = -12,

u= -7,

s= -4,

r= -126.

r = (k*t*u)/s

-126 = (k*-12*-7)/-4

-126 * -4 = 84k

504 = 84k

k = 504/84

k = 6

Find r when t= -8, u= 8, and s= -6.

r = (k*t*u)/s

= (6*-8*8) / -6

= -384 / -6

= 64

r = 64