Answer: 30
Step-by-step explanation: 30 is the first multiple that both 5 and 6 share, and as such should be the denominator
she should add 7 liters of 10% acid solution
Explanation
Step 1
set the equation:
a) let X represents the amount os solution that is 4% acid
let Y represents the amount os solution that is 10% acid
so
I)

if he has 14 liters of 4% acid solution


Step 2
solve the equation :

therefore,
she should add 7 liters of 10% acid solution
I hope this helps you
Let the amount saving by Sienna and Jacob be x
Sienna has $8 and is saving $3 per week
So the equation will be 3x + 8
Jacob has $6 and is saving $4 per week
So the equation will be 4x + 6
Sienna will have same amount as Jacob, so
3x + 8 = 4x + 6
So the model two will represents the equation that Sienna will have same amount as Jacob.
3x + 8 = 3x - 5
3x - 3x + 8 = -5
8 = -5 (incorrect)
this means there is no solution, because whatever number u sub in for x, it will not come out true
Use Desmos, it is a great graphing calculator to help you with stuff like this!