SOLUTION: Please help me answer this question. Determine the constant of proportionality in each of the following direct variations and find the unknown value of the indicated variable. a)

Algebra ->  Linear-equations -> SOLUTION: Please help me answer this question. Determine the constant of proportionality in each of the following direct variations and find the unknown value of the indicated variable. a)      Log On


   

Question 414592: Please help me answer this question.
Determine the constant of proportionality in each of the following direct variations and find the unknown value of the indicated variable.
a) if y varies directly as x, and y=10 when x=5, find y when x=15.
b) If y varies directly as x, and y =5 1/4 when x=3, find x when y=20
c. if the constant of direct variation is 3.75, find x when y=10.
d) if y varies directly as x and the point (3,5) is on the graph of the equation describing the relation, find the equation of the variation
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

a) y = k*x and y=10 when x=5, k = 2   find y when x=15. y+=2%2A15+=+30

b) y = k*x and y =5 1/4 when x=3, k+=+%285.25%29%2F3+=+1.75 find x when y=20  20%2F1.75+=+x

c. if the constant of 'direct variation' is 3.75, find x when y=10. 10%2F3.75+=+x

d) if y varies directly as x and the point (3,5) is on the graph of the equation describing the relation, find the equation of the variation 

   y = kx

   5 = k*3

   5/3 = k    y+=+%285%2F3%29x is the equation of the Direct variation