How many gallons of a 13 % acid solution and a 27 % acid solution need to be mixed to make 7 gallons of a 19 % acid​ solution?

Question

help me i need to get this done. please help

Answer 1

Let X=the amount of 13% acid solution needed.

Next, let 7-X  equal the amount of 27% solution needed

 

So now we need our equation:

 

X gallons of 13% solution + (7-x) gallons of 27% solution = 7 gallons of 19% solution

 

 

Therefore,

.13X + .27(7-X) = 7(.19)

so .13X + 1.89 - .27X = 1.33

then  1.89 - .14X = 1.33

separate the variable

.56 = .14X

4 = X

Plug that amount in to get your answers.