Answer:
C. 3.33 hours
Step-by-step explanation:
Use the algebra work equation:
=
+
, where tb is the time to work together, t1 is the time it takes one person, and t2 is the time it takes the other person
Plug in the values we know:
=
+ 
=
+ 
= 
20 = 6tb
3.33 = tb
So, it would take them 3.33 hours when working together.
Answer: Last Option

Step-by-step explanation:
The initial height of the plant of species A is 25 cm and grows 3 centimeters per month.
If m represents the number of months elapsed then the equation for the height of the plant of species A is:

For species B the initial height is 10 cm and it grows 8 cm each month
If m represents the number of months elapsed then the equation for the height of the plant of species B is:

Finally, the system of equations is:

The answer is the last option
Answer:
4 44/49
Step-by-step explanation:
7 7/9 is 70/9
then u use 70/9 multiply by 7/4(I call it keep, change, flip method for division of fraction)
You keep the 1st fraction and because it is a mixed fraction, changing it to improper fraction is easier to solve it later on.
after that, you change the division sign to multiply sign(÷ to ×)
then you flip the 2nd fraction, which means 7/4 becomes 4/7
So overall it becomes 60/7 × 4/7 =240/49,4 44/49 as a mixed fraction.
Answer is 4 44/49
X=4, y=28. 7x=2x+20, so subtract 2x from both sides and you’ll get 5x=20. Divide both sides by 5 and you’ll get x=4. Substitute this into the other equations and they will both equal 28.