Answer:
x = 6
Step-by-step explanation:
Given that x and y vary directly then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition x = 25 when y = 100 , then
100 = 25k ( divide both sides by 25 )
4 = k
y = 4x ← equation of variation
When y = 24 , then
24 = 4x ( divide both sides by 4 )
6 = x
<span> half life i= 78 hours
amount after 78 hours is 395 kg:
395 = 790e^(k*78)
Dividing by 790 and taking natural log
ln (395/790) = (k*78)
-0.6931 = 78k
-0.00888 = k
lets calculate how much is left after 18 hours:
Amount(18)
= 790e^(-0.00888*18)
Amount = 673.301 kg
hope this helps</span>
Answer:
35
Step-by-step explanation:
7x5= 35
i think pls correct me if im wrong
Answer:

Step-by-step explanation:
Firstly, move over the negative 3/4 fraction (don't forget to swap the operation i.e subtract to add):

Now, to add the two fractions, simply multiply the numerator and denominator by 3:

Now add this to the other fraction:

This can be simplified down by dividing both the numerator and denominator by 4:

Which now simplifies the original equation to:

Remove the y out of the fraction:

Now multiply both sides by 8:



Hope this helps!