Transition To
College
Math
CH 9
Sec 6
Goal for the Day: To learn about Direct, Inverse and Joint Variation
Direct Variation­ is a ratio of the two numbers
x varies directly as y
Inverse Variation­ is a product of the two numbers
w varies inversely as z
Joint Variation­ is when you have two terms in a variation.
a varies jointly as b and c
Combined Variation­ is when you have direct and inverse variations in the same problem
n varies directly as m and inversely as p
x varies directly as y when x = 5 and y = 10, find x if y = 19
w varies inversely as z when w = 6 and z = 2, find z when w = 1/3.
y varies jointly as x and z when y =45 and x = 2 and z = 5. Find y when x = 15 and z = 25.
m varies jointly as b and c and inversely as d
when m = 36, b = 2, c = 3, and d = 12.
Find c when m = 48, b = 2, and d = 6
8 stamps cost $7.50. At the same rate how much would 28 stamps cost?
8 Stamps cost 42 cents while better stamps cost 45 cents. How many 45 cent stamps can you buy for the same price as you paid for the 42 cent stamps?