Determining Variation...1

[nycmathguy]

Section 1.10
Question 37

Determine whether the variation
model represented by the ordered pairs (x, y)
is of the form y = kx or y = kx, and find k.
Then write a model that relates y and x.

Question 37

(5, −3.5),(10, −7),(15, −10.5),(20, −14),(25, −17.5)

 

[MathLover1]

Question 37

(5, -3.5),(10, -7),(15, -10.5),(20, -14),(25, -17.5)

first find k:

y = kx.......use (5, -3.5)
-3.5 = k*5
k=-3.5/5
k=-0.7

y = kx.......use (10, -7)

-7= k*10
k=-7/10
k=-0.7

y = kx.......use (15, -10.5)

-10.5 = k*15
k=-10.5/15
k=-0.7

no need to go further, since k=-0.7 the variation model represented by the ordered pairs (x, y)
is of the form y = kx

Then a model that relates y and x is: y = -0.7x

 

[nycmathguy]

Question 37

(5, -3.5),(10, -7),(15, -10.5),(20, -14),(25, -17.5)

first find k:

y = kx.......use (5, -3.5)
-3.5 = k*5
k=-3.5/5
k=-0.7

y = kx.......use (10, -7)

-7= k*10
k=-7/10
k=-0.7

y = kx.......use (15, -10.5)

-10.5 = k*15
k=-10.5/15
k=-0.7

no need to go further, since k=-0.7 the variation model represented by the ordered pairs (x, y)
is of the form y = kx

Then a model that relates y and x is: y = -0.7x

Very cool. I will try two more similar problems when time allows. Thanks again.