algebra
posted by nmdna .
y varies directly with x. When y = 20, x = 50. Find x when y = 36.

algebra 
Reiny
y varies directly with x > y = kx , where k is a constant
20 = k(50
k = 2/5
y = (2/5)x
when y = 36
36 = (2/5)x
2x = 180
x = 90
or ... use a proportion
x/50 = 36/20
x = 50(36)/20 = 90
Respond to this Question
Similar Questions

algebra1
M varies directly with n; m=144 when n=8. What is the constant of variation k? 
Variation
I have few questions that I need checked please and could you help me with the last question? 
Algebra II
1. If y varies directly as x, and y=30 when x=4, find the constant of proportionality. 2. If y varies inversely as x, and y=2 when x=10, find x when y=4. 3. If a varies jointly as b and c, and a=10, when b=12 and c=2, find a when … 
Math
DIRECT VARIATION 1. a is directly proportional to b.If a=15,then b=9 2. m varies directly as n.If n=2/3,then m=1/4 3. T varies as the square root of L. If L=81,then T=10 4.r varies directly as the square of t. If t=16,then r=6. 5. … 
Math
This is regarding direct variation. y varies directly as the square of R. If y = 128 when R = 8, find y when R = 5. Another one I cannot figure out: If x varies directly as y, and x = 32 when y = 8, find x when y = 10 Help! 
math
t varies directly as the square root of l. If l=81, then t=10 what is the constant proportion? 
MathAlgebra
1. The surface area of a cube varies directly as the square of its edge. Find its surface are. 2. A certain object traveling at 24 meters per second has a kinetic energy of 72 joules. If the kinetic energy of that object varies directly … 
PreCalc
1.) Suppose that y varies directly as x. If y is 5 when x is 30, the constant of variation is 150. True Or False 2.) If w varies directly as z and w = 9 when z = 6, find w when z = 3. 3.) If y varies directly as x and y = 2 when x … 
PreAlgebra
If y varies directly with x, find the constant of variation with x = 4 and y = 24 If y varies inversely with x, find the constant of variation with x=5 and y = 10 If y varies directly with x, and y = 35 when x = 5 , find x when y … 
Math/Algebra
Im stuck on two problems and would really appreciate the help. 1. y varies jointly as a and b, and inversely as the square root of c. y=28 when a=2, b=7, and c=9. Find y when a=4, b=2, and c=4 2. y varies directly as x and inversely …