How many gallons of 20% salt solution must be mixed with 4 gallons of 40% salt solution to make 25% salt solution?

12 gallons of 20% salt solution

Step-by-step explanation:

Let

x > the number of gallons of 20% salt solution

we know that

20%=20/100=0.20

40%=40/100=0.40

25%=25/100=0.25

so

0.20(x)+0.40(4)=0.25(x+4)

Solve for x

0.20x+1.60=0.25x+1

0.25x-0.20x=1.60-1

0.05x=0.60

x=12 gallons

perimeter = 10 +  √10  units

explanation:

first, we will need to get the length of each line using the distance formula which is as follows:

distance = 

1- length of ab:

ab =   = 5 units

2- length of ac

length of ac is the same as ab = 5 units

3- length of bc:

bc =   =  √10  units

now, we can get the perimeter by adding the side lengths as follows:

perimeter = 5 + 5 +  √10

perimeter = 10 +  √10  units

hope this : )

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her total is 2

  -3+5=2