Answer:
=−3
Step-by-step explanation:
=17a+−37−121a+17
=21(a−3)7(−a+3)
=−3
Step-by-step explanation:
9v-4v+7v
= 5v+7v
= 12v
The answer is 12v
Answer:
The perimeter is 6x+8
Step-by-step explanation:
2(2x+3) +2(x+1)
4x+6+2x+2
6x+8
Answer:
Therefore the concentration of salt in the incoming brine is 1.73 g/L.
Step-by-step explanation:
Here the amount of incoming and outgoing of water are equal. Then the amount of water in the tank remain same = 10 liters.
Let the concentration of salt be a gram/L
Let the amount salt in the tank at any time t be Q(t).

Incoming rate = (a g/L)×(1 L/min)
=a g/min
The concentration of salt in the tank at any time t is =
g/L
Outgoing rate =



Integrating both sides

[ where c arbitrary constant]
Initial condition when t= 20 , Q(t)= 15 gram


Therefore ,
.......(1)
In the starting time t=0 and Q(t)=0
Putting t=0 and Q(t)=0 in equation (1) we get









Therefore the concentration of salt in the incoming brine is 1.73 g/L