Answer:
c = 360/n
Step-by-step explanation:
From the question, we are told that:
The cost per ounce of a drink, c, varies inversely as the number of ounces, n.
Mathematically this is expressed as:
c ∝ 1/n
Using the constant of proportionality k
c = k/n
Six ounces of the drink costs 60 cents per ounce.
c =60 cents per ounce
n = 6 ounces
Mathematically we have
c = k/n
60 = k/6
Cross multiply to find the constant k
k = 60 × 6
k = constant of proportionality = 360
Therefore, using the mathematically expression "c = k/n" the equation that represents this relationship is
c = 360/n
Answer:
7 years
Step-by-step explanation:
Given that:
Let Richard's age = x
Elder sister's age = 2x
Youngwr sister's age = x - 2
Product of sisters ages = 70
2x * (x - 2) = 70
2x² - 4x = 70
2x² - 4x - 70 = 0
x² - 2x - 35 = 0
x² - 7x + 5x - 35 = 0
x(x - 7) +5(x - 7) = 0
(x - 7) or (x + 5) = 0
x = 7 or x = - 5
X can't be negative
Hence, x = 7
Richard is 7 years
X + x + x + x - 20 is equivalent to 4x - 20 because you can add the like terms, or the x's.
