Answer:
Tell her to do more practices in math. You can also recommend her here at Brainly if she finds hard questions to solve.
Step-by-step explanation:
The population 150 students
The sample is 54% of students
I’m not sure but I hope this helps!
Solve for m:3 m + 7/2 = 5/2 - 2 m
Put each term in 3 m + 7/2 over the common denominator 2: 3 m + 7/2 = (6 m)/2 + 7/2:(6 m)/2 + 7/2 = 5/2 - 2 m
(6 m)/2 + 7/2 = (6 m + 7)/2:(6 m + 7)/2 = 5/2 - 2 m
Put each term in 5/2 - 2 m over the common denominator 2: 5/2 - 2 m = 5/2 - (4 m)/2:(6 m + 7)/2 = 5/2 - (4 m)/2
5/2 - (4 m)/2 = (5 - 4 m)/2:(6 m + 7)/2 = (5 - 4 m)/2
Multiply both sides by 2:6 m + 7 = 5 - 4 m
Add 4 m to both sides:6 m + 4 m + 7 = (4 m - 4 m) + 5
4 m - 4 m = 0:6 m + 4 m + 7 = 5
6 m + 4 m = 10 m:10 m + 7 = 5
Subtract 7 from both sides:10 m + (7 - 7) = 5 - 7
7 - 7 = 0:10 m = 5 - 7
5 - 7 = -2:10 m = -2
Divide both sides of 10 m = -2 by 10:(10 m)/10 = (-2)/10
10/10 = 1:m = (-2)/10
The gcd of -2 and 10 is 2, so (-2)/10 = (2 (-1))/(2×5) = 2/2×(-1)/5 = (-1)/5:Answer: m = (-1)/5
Answer:
Step-by-step explanation:
Amount of brine = 100 gal
amount of salt = 80 lb
rate of water running = 4 gal / min
Let A be the amount of salt in lb in the tank at any time t.
(a) dA/dt = rate of salt in - rate of salt out
Rate of salt in = 0
rate of salt out = A x 4 / 100 = A / 25 lb/min
So, dA/dt = 0 - A/25 = - A/25 lb/min
When t = 0, A = 80 lb
So,
(b) Now, A = 40 lb
So,
take log on both the sides
t = 17.3 minutes
