Rocky ate 42 cups of dog food. Since there are 7 days in a week, 21 cups were eaten per week (3x7). Since the question is asking for the amount in two weeks, you multiply 21x2 to get 42.
Answer:
Adult=58
Step-by-step explanation:
c=child, a=adult
6.4c+9.7a=1145 equation 1
c+a=149 equation 2
a=149-c modified equation 2 to isolate a
6.4c+9.7(149-c)=1145 substitute value of a from equation 1 into equation 2
6.4c+1445.3-9.7c=1145
-3.3c=-300.3
c=91
solve for a
c+a=149
91+a=149
a=58
Check answer:
6.4c+9.7a=1145
6.4(91)+9.7(58)=1145
582.40+562.60=1145
1145=1145
5.) Answer: 0.45
Step-by-step explanation:
There is 1.5 quarts of paint, and 30% is yellow.
30% of 1.5 is 0.45.
6.) Answer: 7.198
Step-by-step explanation:
$499.99 is 100%. We need to find $35.99 off of it in percentage.
499.99/35.99 = 100/x
499.99x = 3599, x = 3599/499.99
x ≈ 7.198
Answer:
26 inches
Step-by-step explanation:
Direct variation is a relation that has the form
y = kx
where k is the constant of proportionality.
If you are told that a relation is a direct proportion, and you are given one data point, you can find k. The you can write the equation of the direct relation.
Here is an example.
The price of gasoline follows a direct variation.
John bought 5 gallons of gas and paid $15.
a) Write an equation for the relation.
b) Using the relation you found, how much do 13.8 gallons cost?
Solution:
Since the relation is a direct variation, it follows the general equation of a direct variation:
y = kx
We are given one data point, 5 gallons cost $15.
We plug in 5 for x and 15 for y and we find k.
y = kx
15 = k * 5
k = 3
Now that we know that k = 3, we rewrite the relation using our value of k.
y = 3x
This is the answer to part a).
Part b)
We use our relation, y = 3x, and we plug in 13.8 into x and find y.
y = 3x
y = 3 * 13.8
y = 41.4
The price of 15 gallons of gas is $41.40.
