Let y and x be the numbers that varies directly (that means they keep the same proportion)
Then we have 7y = 3x, OR y/x =7/3 (this ratio should be kept for any value of x and y:
y/x = 7/3, if y = 28, then 28/x = 7/3 or x = (3)(28)/7 = 12
SO X = 12
Answer:
-9
Step-by-step explanation:
divide by minus nine

is the answer I can also give you the graph to if you need it, but that's how you would graph it. : ) Let me know if you need the graph
I would find it easiest to reduce the number to minutes, like this: 500 in 20 minutes would be 500 divided by 20 = 25 pteradactyls /min.
There are 90 minutes in an hour and a half, so 25 x 90 = 2,250 pteradactyls in 1 1/2 hours.
Answer:
odd
Step-by-step explanation:
To determine if odd/ even
• If f(x) = f(- x) then it is even
• If f(- x) = - f(x) then it is odd
Given
f(x) = 4x³ - 5x , then
f(- x) = 4(- x)³ - 5(- x) = - 4x³ + 5x
Since f(x) ≠ f(- x) then it is not even
- f(x) = - (4x³ - 5x) = - 4x³ + 5x
Since f(- x) = - f(x) , then 4x³ - 5x is odd