how many ounces of 7% acid solution and how many ounces of a 23% acid solution must be mixed to obtain 20 oz of a 17% acid solution?

7.5 ounces of  7% acid solution is mixed with 12.5 ounces of 23% acid solution to obtain 20 oz of a 17% acid solution.

Step-by-step explanation:

Let x = Ounces of 7% acid solution

y=  Ounces of 23% acid solution

According to the question , we have two linear equations:

x+y=20    

i.e. y=20-x  ...(i)

0.07 x+ 0.23y =0.17 (20)

i.e.  0.07x+0.23y= 3.4 ...(ii)

Substitute value of y from (i) in (ii) , we get

0.07x+0.23(20-x)= 3.4

⇒ 0.07x+4.6-0.23x=3.4   [distributive property]

⇒ 0.07x-0.23x=3.4-4.6 [subtract 4.6 from both sides]

⇒ -0.16x=-1.2

⇒  x = 7.5    [divide both sides by-0.16]

put value of x in (i) , we get y= 20-7.5 =12.5

Hence, 7.5 ounces of  7% acid solution is mixed with 12.5 ounces of 23% acid solution to obtain 20 oz of a 17% acid solution.

5

step-by-step explanation:

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer