So i know everybody says that they need help asap and stuff, and tbh i have until umm 11:59 to turn this in so if u get to this later thats cool too. thx guys : Sally Smith is a chemist with XYZ Pharmaceutical. She mixes a 9% solution of sulfuric acid with a 30% solution of sulfuric acid to produce an 18% solution. How much 9% solution and how much 30% solution will be needed to make 21L of 18% solution?

You should read more because is easy

Step-by-step explanation:

well its going to be less then 18 so 12

Step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places